- List: $48,350
-
40ft long
-
14,344 lbs
-
Sleeps 6
-
4 slides
-
BunkhouseRear Living Area
378MBS Floorplan
Specifications
| Sleeps | 6 | Slides | 4 |
| Length | 40 ft 2 in | Ext Width | 8 ft 5 in |
| Ext Height | 13 ft 5 in | Hitch Weight | 2686 lbs |
| GVWR | 16800 lbs | Dry Weight | 14344 lbs |
| Fresh Water Capacity | 93 gals | Grey Water Capacity | 100 gals |
| Black Water Capacity | 50 gals | Tire Size | 16" |
| Furnace BTU | 40000 btu | Number Of Bunks | 1 |
| Available Beds | Queen | Refrigerator Type | Stainless Steel Four Door |
| Refrigerator Size | 18 cu ft | Cooktop Burners | 3 |
| Number of Awnings | 2 | Axle Weight | 7000 lbs |
| LP Tank Capacity | 60 lbs | Water Heater Capacity | 12 gal |
| Water Heater Type | Gas/Electric | AC BTU | 30000 btu |
| TV Info | LR LED Smart TV, BR LED TV | Awning Info | 20' and 11' Power with LED Lights |
| Axle Count | 2 | Washer/Dryer Available | Yes |
| Shower Type | Shower w/Seat | Electrical Service | 50 amp |
| VIN | 573FS4229MAA05655 |
Description
Experience true residential luxury on the road with this Preowned 2021 Grand Design Solitude 378MBS—a fifth wheel designed for extended stays, full-time living, or unforgettable family adventures. With its spacious mid-bunk layout, premium amenities, and high-end construction, this RV delivers the perfect blend of comfort, functionality, and style.
Stretching just over 40 feet in length with four expansive slide-outs, the Solitude 378MBS creates an open, residential feel that’s hard to match. Inside, you’ll find a beautifully appointed rear living area featuring plush seating, theater recliners, a large entertainment center, and a cozy fireplace—perfect for relaxing after a day of exploring. Large panoramic windows flood the space with natural light, making every destination feel like home.
One of the standout features of this model is the versatile mid-bunk room. Whether you need a private guest bedroom, home office, or kids’ hangout, this flexible space includes a sofa sleeper, bunk, storage, and workspace—making it ideal for modern travelers who want options.
The gourmet kitchen is designed to impress, offering solid surface countertops, a residential-size refrigerator, large pantry, hutch, and ample cabinet storage. Whether you’re cooking for two or entertaining a group, you’ll appreciate the thoughtful layout and abundant prep space.
Up front, the private master suite delivers a true retreat with a comfortable bed, large wardrobe, washer/dryer prep, and plenty of storage. The spacious bathroom features a large shower, porcelain toilet, and quality finishes that elevate your daily routine.
Built with Grand Design’s commitment to quality, this Solitude includes features like aluminum frame construction, fiberglass exterior, high-capacity holding tanks, and climate protection for extended-season camping. With a 93-gallon fresh water tank, 100-gallon gray tank, and sleeping space for up to 7, this unit is ready for long trips or full-time living.
Why buy the 2021 Grand Design Solitude 378MBS?
This is one of the most sought-after floorplans in the luxury fifth wheel market thanks to its mid-bunk versatility and residential feel. It’s perfect for families, remote workers, or anyone wanting a dedicated bonus room without sacrificing living space. Buying preowned means you get top-tier luxury and features at a significantly better value than new, making it a smart investment for serious travelers.
Why buy from Lazydays Powered by Campers Inn RV?
Lazydays Powered by Campers Inn RV offers a trusted, customer-first experience backed by one of the most recognized names in the RV industry. With a massive inventory, competitive pricing, and experienced RV professionals, they make it easy to find the perfect unit for your lifestyle. Their commitment to quality inspections, flexible financing options, and ongoing service support ensures confidence long after your purchase. From your first walk-through to every mile ahead, you’re supported by a team that truly understands the RV lifestyle.
If you’re ready to elevate your travel experience with residential comfort, versatile living space, and premium design, this 2021 Grand Design Solitude 378MBS is the perfect choice. Your next chapter of adventure starts here.
Features
Standard Features (2021)
Construction
- Drop Frame Chassis
- Upgraded Axle Hangers
Audio & Video
- LED TV in Master Bedroom (Mandatory)
- King Jack Antenna
- Solar Prep
Bathroom
- One-Piece Fiberglass Shower with Glass Door
- Porcelain Toilet
- Undermount Lav Sink
Bedroom
- Residential Style Headboard
- Under Bed Storage Area
- Individually Switched Reading Lights Over Bed
- 60" x 80" Queen Bed (NA 385GK)
- King Bed (Std 385GK) (Optional)
- Window Above Master Bed Headboard
Exterior
- Heavy Duty G-Rated Tires w/NitroFill™ (Mandatory)
- Dual Pane Windows (Optional)
- Slide Out Awning Toppers (Optional)
- 6-Point Hydraulic Leveling System (Mandatory)
- Front Cap Windshield (3550BH, 2930RL, 380FL, 382WB)
- Back-Up Camera Prep
- Full Body Paint (Optional)
- Under Unit LED Light Kit
- Pull-Out Kitchen (In Pass-Through) (NA 378MBS) (Optional)
- Tire Linc TPMS System
HVAC & Plumbing
- Heat Pump A/C Upgrade in Living Area (Optional)
- Fireplace with Electric Heater (Mandatory)
- 12 Gallon Gas/Electric Water Heater
- Exterior Spray Port (Door Side)
Interior
- Double Tri-Fold Hide-A-Bed Sofas (375RES, 377MBS, 380FL, 382WB, 390RK)
- Leaded Glass Cabinet Door Inserts (Select Areas)
- Under Step Shoe Storage (Most Models)
- Plywood Drawer Bottoms
Kitchen
- Oversized Kitchen Pantry
- LED Rope Lighting in Pantry
- Residential Kitchen Faucet with Pullout Sprayer
- Professional Grade Stainless Steel Cooktop w/ Built-in Oven
- Real Tile Backsplash
- Hardwood Kitchen Light Soffit
- Dishwasher Prep (310GK, 344GK, 372WB, 373FB, 385GK)
- Stainless Steel 18 Cu. Ft. 4-Door Refrigerator (Mandatory)
- Residential Stainless Steel French Door Refrigerator (IPO 18 cu. ft. RV Refrigerator) (Optional)
- Hutch with Flip-Top Hidden Storage (380FL, 382WB, 390RK)
- Microwave (Mandatory)
Utilities
- 55 Amp Converter
- 12V Tank Heaters (Mandatory)
- Generator Prep (Optional)
- Onan 5.5kw LP Generator (Requires Generator Prep) (Optional)
- Solar Prep (10 gauge wiring with universal MC4 connectors)
- Solitude Solar System (300w Solar Panel, Controller, 2000w Inverter) (Optional)
Options
- 7K Axles with Disc Brakes (Not Available in Canada)
- 8K Axles with Disc Brakes and H-Rated Cooper Tires (Not Available in Canada)
Packages
Max Built Construction Package (Mandatory)
- Satellite/Cable Prep (All TV Locations)
- 101" Wide body Construction
- Heavy Duty 7,000 lb. Axles
- 16" Aluminum Wheels
- High-Gloss Gel Coat Exterior Sidewalls
- Color Matched Fender Skirt
- 5-Side Aluminum Cage Construction
- Walk-On Roof
- TPO Roof Covering w/ 12-Year Warranty
- Slam-Latch Baggage Doors
- Magnetic Entry and Baggage Door Catches
- Entry Door w/Privacy Glass
- Frameless Tinted Windows
- Painted Gel Coat Fiberglass Front Cap
- Exterior Security Light
- Roof Ladder
- 50 Amp Service w/Detachable Power Cord
- 12-Volt Battery Disconnect
Peace of Mind Package (Mandatory)
- Exterior Cable/Satellite Plug-In
- Pull-Out Ottoman at Bed Base (N/A 373FB)
- Dresser w/ Flip-Top Hidden Storage (NA 380FL, 382WB)
- MORryde Pin Box
- MORryde CRE3000 Suspension System
- Self Adjusting Brakes
- 16" Spare Tire (Undermount)
- Slide-Out Selector Valves
- Power Patio Awning with Integrated LED Lighting
- Sewer Hose Storage Area
- Kitchen 12-Volt High Power MaxxAir Fan with Rain Sensor
- Washer/Dryer Prep
- Whole House Water Filtration System
- Easy Clean Solid Surface Steps
Residential Living Package (Mandatory)
- LED Smart TV in Living Area
- Rockford Fosgate Stereo Ent. System w/ HDMI and App Controls
- Exterior Speakers
- Night Stands with USB Ports
- Bedside 110-Volt Outlets (2)
- Keyed Alike (One Key For All Entry and Baggage Doors)
- SolidStep Quad Entry Steps
- Stealth A/C System (Dual AC's w/Racetrack Ducting)
- Roller Shade Window Coverings
- Hardwood Window Treatments
- Congoleum Flooring w/3-Year Warranty
- Hallway Handrail
- Recessed LED Ceiling Lighting
- Interior LED Accent Lighting
- Hardwood Cabinet Doors
- Signature Wall Mounted Dinette Table w/ 4 Padded Chairs (2 Stow Away Chairs)
- Power Reclining Theatre Seating w/Swivel Tables (Includes LED Lighting, Heat and Massage Function)
- Tri-Fold Hide-A-Bed Sofa
- Smoke Detector, LP Alarm, Carbon Monoxide Alarm
- Solid Surface Countertops & Sink Covers
- Stainless Steel Undermount Kitchen Sink
Weather-Tek Package (Mandatory)
- 35k BTU High Output Furnace
- Fully Enclosed Underbelly w/Heated Tanks and Storage
- Attic Vent
- High Capacity Heat Ducts
- All-in-One Enclosed and Heated Utility Center
Please see us for a complete list of features and available options!
All standard features and specifications are subject to change.
All warranty info is typically reserved for new units and is subject to specific terms and conditions. See us for more details.
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*All calculated monthly payments are an estimate for qualified buyers only and do not constitute a commitment that financing or a specific interest rate or term is available. Financing terms may not be available in all Campers Inn locations. Campers Inn RV Sales is not responsible for any misprints, typos, or errors found in our website pages. Any price listed excludes sales tax, registration tags, and delivery fees. Manufacturer pictures, specifications, and features may be used in place of actual inventory in stock on our lot. Please contact us for availability as our inventory changes rapidly.
Manufacturer and/or stock photographs may be used and may not be representative of the particular unit being viewed. Where an image has a stock image indicator, please confirm specific unit details with your dealer representative.
Manufacturer and/or stock photographs may be used and may not be representative of the particular unit being viewed. Where an image has a stock image indicator, please confirm specific unit details with your dealer representative.



