BMW Chassis Reinforcement Kits & Parts for BMW E46 M3 S54 (1999-2005)

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Made in the USAAs much of an "Ultimate Driving Machine" it is, many BMW models unfortunately suffer from weak points in the chassis. Over the years we have uncovered many weak or failure-prone areas in the chassis and have developed our own reinforcing solutions for them. And we continue to be the leading experts on BMW chassis reinforcing. Failures can come from a number, or combination, of causes: improper maintenance, age and mileage, poor design, environmental factors, poor repair work, and over-stressing modifications. The longer you let your car go without repairing or reinforcing these areas, the closer it gets to crumbling apart. Our chassis reinforcement kits are designed to first identify potential weak points and then strengthen and reinforce the existing design.

Most of our kits are not labor intensive although welding is usually required. If you suspect your chassis may have structural problems we recommend taking it to a well-known bodyshop or restoration shop. (find out who your local BMW dealer uses - we sell many of our kits to dealer-authorized repair shops). Making the preventative fix simple and effective is better than a long and complicated repair after the failure. Our kits are not usually used for fixing existing damage (only your body shop can determine the correct course of action). But our kits have been proven under extreme conditions on racetracks around the world to prevent many of the costly - and dangerous - chassis problems.
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Rogue Engineering - Corporate Logo
T#:12643107
Part#: RE.899
Ships in 9 Business Days
$ 595.00 USD
Free Shipping on orders $49 and up
An integral part on E46 M3 is the rear chassis "V-Brace" (BMW # 33312229899) found on all 2001-06 Convertibles and Coupe (including the CSL). This brace attaches to the outward points of the rear chassis and to the area near the rear subframe carrier. Since some of these vehicles are now over 20 years old, we have been seeing more and more of these start to rust away. We began studying the OEM part, curious as to why they were starting to rust away. We found that the two arms of the "V" are made from 38mm x 12mm (1.5" x 0.5") hollow square steel tubing, pressed ends and welded to a junction plate joining them with welds holding the arms at a specific angle. Since the arms are hollow, it helps keep the overall weight down, but does little to prevent corrosion since it is difficult to paint/coat a hollow tube. A Google search turned up very little other than used ones on eBay and new ones that turned out to be in short supply from the BMW dealer (not surprising since the car is over 20 years old). Determined to make something better, we began our engineering and R&D process. Goals of our Design; Modular design, since packaging and shipping something this large would probably be too expensive Costs would dictate material and manufacturing methods Lighter weight would be a secondary (or tertiary) goal, but also keeping in mind costs Corrosion resistant, so it would not rust from the inside out, like the OEM version After weighing the material, manufacturing and cost options, we decided to go with a fully CNC'd ACQ 6061-T6 aluminum assembly. The concept is to machine two identical arms (one part number) and have them joined with a "junction plate". The arms would be secured to the plate with Grade 8.8 grade hardware and the entire assembly would include replacement Grade 10.9 hardware to replace the original OEM hardware (which is probably original). Details of our Design; CNC'd 6061-T6 construction, secured with Grade 8.8 socket head cap screws. Included are replacement Grade 10.9 hardware to fit in the factory locations. About 4 lbs. fully assembled weight (vs. 6.25 lbs for OEM), about a 35% weight savings Anodized gray finish Modular design allows for one arm to be removed in case of exhaust removal requirement. Included in the Kit Two (2) arms of the brace assembly (they are idential) One (1) junction plate One (1) red spacer (this goes BETWEEN the brace and the chassis!) Two (2) blue spacers (these goes BETWEEN the brace and the chassis!) Four (4), M10 socket head cap screws Three (3), M10 flanged hex head bolts It is recommended that the holes used to mount the V-brace onto the car be cleaned before installation by running an M10x1.5 tap to clean each of the holes.
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Bavarian Autosport - Corporate Logo
T#:578621
Part#: B3300044
In Stock
Sale - Save 3% $ 8.99

This product was last offered at the strikethrough price on
05-03-2026

$ 8.68 USD
Free Shipping on orders $49 and up
Sale - Save 3%
$ 8.99

This product was last offered at the strikethrough price on
05-03-2026

$ 8.68 USD
Free Shipping on orders $49 and up
This is a direct replacement for the factory BMW rear shock mount reinforcement, as equipped by BMW on Z3 models. This also fits all E36 and E46 models as well. Turner Motorsport makes our own that are thicker but these can also do a good job of preventing cracks and deformation of the rear shock towers. Priced per reinforcement plate. Order 2 to cover both rear shock towers. From 1974 to 2019, Bavarian Autosport was one of the premier vendors for BMW and MINI auto parts. We are happy to preserve the Bav Auto legacy by continuing to carry their high-quality products into the future. All Bav Auto parts will remain unchanged in design and sourced from the same OEM suppliers to ensure long-lasting reliability. We trust these parts, accessories, and upgrades so confidently that we back every Bavarian Autosport branded component with a 2-year warranty. This item fits the following BMWs: 1992-1999 E36 BMW 318i 318is 318ti 318ic 323is 325i 325is 328i 328is M3 (not for convertible models) 1999-2006 E46 BMW 323i 323ci 325i 325ci 325xi 328i 328ci 330i 330ci 330xi M3 (not for convertible models) 1997-2002 Z3 BMW Z3 1.9 Z3 2.3 Z3 2.5i Z3 2.8 Z3 3.0i M Roadster M Coupe
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