BBT Napoleon Hat Center Chassis Support — VW Beetle, Karmann Ghia & Thing (98-5328-B)

Short answer: This is the BBT reproduction "Napoleon Hat" center chassis support (98-5328-B, VW 113-701-131), the weld-in structural stamping under the rear seat that ties the floor pan tunnel to the body. It fits the standard VW Beetle 1949–1977 (including the Convertible), the Karmann Ghia 1956–1974 and the 1973–1974 Thing in left-hand-drive configuration. It does not fit the Super Beetle.

BBT center chassis support — commonly called the "Napoleon Hat" for its distinctive shape — for VW Beetle, Karmann Ghia, and Type 1 Convertible. Stamped reproduction sheet metal replacement for the structural support piece that ties the floor pan tunnel to the body. EMPI / BBT part #98-5328-B.

What the Napoleon Hat is and why it matters structurally

The Napoleon Hat is the curved, hat-shaped stamping that sits under the rear seat of an air-cooled VW Beetle, bridging the floor pan tunnel and tying it into the body structure. It's a critical structural member — particularly on Convertible Beetles, which rely on additional body bracing to compensate for the lack of a fixed roof. The factory part is heavily prone to rust because it sits below seat-line where moisture, debris, and decades of leaks accumulate.

Once the original Napoleon Hat rusts through, the floor pan tunnel and rear seat support lose their structural connection to the body. The car still drives, but body flex increases, doors stop aligning correctly, and rust spreads to adjacent structure. Replacing it during a floor pan or rust restoration is the right time — it's far more accessible with the body off or with the rear seat area exposed.

Specifications

• Manufacturer: BBT (Belgian reproduction sheet metal specialist)
• Function: Structural support tying floor pan tunnel to body, under rear seat
• Installation: Weld-in replacement
• Part number: 98-5328-B (BBT) / VW reference 113701131
• Configuration: Left-hand drive (LHD) standard

Fitment

• VW Beetle (standard, not Super Beetle): 1949–1977
• VW Beetle Convertible (standard-chassis Type 1 Cabriolet): through 1970
• VW Karmann Ghia (Type 14): 1956–1974
• VW Thing (Type 181): 1973–1974
• Does not fit: Super Beetle 1302/1303, which uses a different center chassis support (VW 133-701-131)

Note: Standard configuration is left-hand drive. RHD cars (UK, Australia, South Africa) may require modification or a different part. Confirm with us before ordering for an RHD application.

FAQ

Why is it called a "Napoleon Hat"?
The bicorn shape of the stamping resembles the hat Napoleon famously wore — a tradition of VW restoration slang that goes back decades. The part has no official name in factory VW parts catalogs other than its part number.

Can I install this without dropping the body?
You can, but it's significantly easier with the body off or with the floor pans and rear seat area substantially exposed. Most restorers install the Napoleon Hat during a broader floor pan or chassis restoration when the area is already open.

Does this come with the rear seat bracket?
This is the Napoleon Hat structural piece only. Additional rear seat mounting brackets and surrounding sheet metal may need separate replacement depending on the extent of your rust.

Is BBT quality equivalent to original German?
BBT is one of the better reproduction sheet metal manufacturers — Belgian, well-known in European VW restoration circles, and generally accepted as the closest reproduction match to original German stamping quality. Not identical to NOS German, but very close.

Will this fit a Super Beetle?
No. The Super Beetle (1302/1303) uses a different center chassis support, VW 133-701-131. This one (VW 113-701-131) is for the standard Beetle, Karmann Ghia and Thing.

Do I need to coat or treat it before welding?
We recommend stripping any factory coating from the weld areas, welding it in, then sealing and undercoating the area properly to prevent the new piece from rusting out the same way.

Does this fit a 1967 VW Beetle?
Yes. It fits the standard VW Beetle 1949–1977 (including the Convertible), the Karmann Ghia 1956–1974 and the 1973–1974 Thing. It does not fit the Super Beetle.

What is the part number?
BBT 98-5328-B, VW reference 113-701-131. The Super Beetle part is a different number, VW 133-701-131.

Prop 65 Warning

WARNING: This product can expose you to chemicals including lead, which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.