BAKFlip MX4 Hard Folding Tonneau Cover
We built the BAKFlip MX4 for truck owners who need a low-profile hard cover that won't compromise bed access. Four aluminum panels fold completely open in seconds, stacking against the cab to give you 100% of your bed when you need it. The matte finish resists UV fade and hides fingerprints better than gloss alternatives, while the FRP-reinforced panels handle snow load and daily abuse without flexing.
Every MX4 sits flush inside the bed rails for a factory-clean look. The dual-action tailgate seal keeps water out during highway rain, and the automatic latch system locks each panel independently at the rail. You get full bed utility without removing a single component.
Core specs & construction
Panel Construction & Weather Resistance
Each MX4 panel starts with an aluminum skin laminated over a fiber-reinforced polymer core—the same composite layup we use across our hard-folding lineup. That FRP core adds stiffness without the weight penalty of solid metal, so you can fold the cover one-handed without straining the hinges. The matte powder coat is baked at 400°F to lock pigment into the surface; it won’t chalk or fade under full desert sun the way cheaper gloss finishes do.
Water management comes down to the dual-action tailgate seal. One foam channel runs the full width of the bed, pressing against the tailgate when closed. A second side-rail seal overlaps every panel joint, creating a labyrinth path that blocks wind-driven rain. We can’t promise bone-dry—no tonneau cover is submarine-tight—but highway spray and car-wash runoff stay outside the bed.
Folding Access & Load Flexibility
Full Fold-Back
Pull the strap loops and the MX4 accordion-folds in under ten seconds, stacking all four panels upright against the cab. That gives you the entire bed floor for plywood, a dirt bike, or a refrigerator—anything that needs vertical clearance. The folded stack sits 12 inches off the bed floor, so shorter cargo still slides underneath.
Partial Positions
You’re not locked into all-or-nothing. Fold back two panels to load from the tailgate while keeping the front half locked. Or fold just the rear panel for quick grocery runs. Every panel latches independently at the rail, so you choose how much bed to expose.
Installation & Bed-Rail Compatibility
The MX4 clamps directly to the top inner edge of your bed rails—no drilling, no adhesive. Each side rail carries four clamps that you tighten with a standard 10mm socket. The whole install takes 30 minutes if you’ve never done it before; 15 minutes once you know the sequence.
Factory spray-in liners and drop-in bedliners work fine as long as the rail lip is still accessible. If you have a thick over-rail liner that covers the clamp surface, you’ll need to trim it back or remove it. Our fit guide lists specific compatibility notes for each truck year and trim package—check your VIN before ordering if you’re running aftermarket bed accessories. The front header panel adjusts fore and aft to match cab-gap variation across different truck generations, ensuring a clean seal whether you drive a 2015 or a 2024 model.
Other BAKFlip Hard Folding Covers
Rated 4.8 by verified buyers
Common Questions About the BAKFlip MX4
Yes, the MX4 works with most factory and aftermarket spray-in liners as long as the top inner edge of your bed rail is still exposed for the clamps to grip. If your liner wraps over the rail edge, you'll need to trim it back slightly. Drop-in liners also work—just ensure the liner doesn't push the rail clamp points outward.
The MX4 is rated for up to 400 pounds evenly distributed across all four panels. That's enough for light foot traffic when you need to reach the front of the bed or for stacking gear on top during a camping trip. Do not use it as a permanent roof rack or concentrate heavy weight on a single panel, as that can stress the hinges.
No, we do not recommend driving with any panels in the upright folded position. Wind force at highway speed can damage the hinges or cause the panels to slam shut unexpectedly. Always secure all panels flat and latched before driving, or remove the cover entirely if you need open-bed transport.
Minimal upkeep keeps the MX4 performing well for years. Rinse the panels and seals every few months to clear dirt and road salt. Lubricate the hinge pivot points once a year with silicone spray—avoid petroleum-based oils that can degrade the seals. Check clamp tightness every six months, especially if you fold and unfold the cover frequently.
The MX4 is highly water-resistant but not submersion-proof. The dual-action tailgate seal and overlapping panel joints block the vast majority of rain and car-wash spray. In extreme weather—heavy downpours, snow melt, or pressure washing—some moisture may seep through. For sensitive electronics, we recommend using a secondary tarp or waterproof case inside the bed.
Yes, when folded completely open and stacked against the cab, the MX4 clears most fifth-wheel hitches and provides full bed access for towing. Confirm your specific hitch model's height and cab-clearance requirements before ordering. Some low-profile gooseneck hitches may require removing the front header panel during towing.
We back the MX4 with a lifetime warranty on the aluminum panel frames and FRP core against structural failure. Seals, hinges, and finish carry a five-year warranty covering defects in materials and workmanship. Normal wear from UV exposure, road debris, or improper installation is not covered. Registration within 30 days of purchase is required for full warranty protection.