BimmerWorld E46 M3 Rear Diffuser

Functional and professional race-quality diffuser for track or street

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Close out your lower rear bumper and add rear downforce

Our BimmerWorld E46 M3 Rear Diffuser is race-bred and functional, but it's also perfectly at home on a street car. As with all of our professional-quality carbon, this piece is bagged and autoclaved to be
 extremely strong and light - surface finish is straight out of the mold with no additional weight or clearcoat added as is typical for our racing applications; you may choose to have your local body shop finish for ultimate aesthetics and UV protection for high-end street and show car applications. Our diffuser extends all the way forward to the factory rear fuel evaporation box, which provides the axle-back flat floor from the factory.

The diffuser attaches to your stock bumper trim mounting points, and it requires slight modification of the fuel evap. box, plus reversible modifications to the bumper.

Designed for use with our BimmerWorld E46 M3 Exhaust line - this exhaust section is designed specifically for use with this diffuser. The diffuser doesn't work with any exhaust section using the standard left cutout in the stock factory bumper insert. 

BimmerWorld race carbon parts are designed solely to improve performance. Surface finish and appearance are not priorities in our racing parts. Carbon may be unfinished or sometimes with a minimal clearcoat (for UV protection). You will not find high gloss finishes here for style points. If your priorities are a show car shine there is no shortage of cheaper carbon-wrapped fiberglass or plastic pieces on the market. These are usually loaded with fiberglass, filler, resin, and many clearcoat layers that make them too heavy or not rigid enough for real world competition use. If you wish to apply a finish we suggest vinyl wrap or a light filler skim coat and then paint. In any case, professional prep and installation are strongly advised.

BMW Fitments:

3 Series
E46 (99-05) > M3
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What customers are saying...

  • I am extremely pleased with this order. The price was competitive and your expedited delivery charge was surprisingly low. I needed the part fast and you exceeded my expectations. I especially appreciate your gentleman who over the phone ensured me that the part was indeed in stock and would be shipped immediately.
    - Allan Read More
  • I’ve never dealt with a true “race” shop like BW and I really have enjoyed the experience. I always feel like I’m getting the best advice, and suggestions for true race car set up. Your technical expertise on even the minute details of building race cars is really impressive, and some I value greatly...
    - Paul Read More
  • I just can't express enough how impressed I am with you guys. Thanks so much for the great service from start to finish, and always done with a smile and as professional as possible. Our particular interaction has extended over many months and never have I felt that I wasn't getting first-class service...
    - Chris Read More
  • I just wanted to say what positive experiences I've had over the past few weeks. Your BimmerWorld sales staff have gone above and beyond to help me out, between their service and taking the time to answer all my questions, I'll be buying my parts from BimmerWorld whenever possible...
    - Aaron Read More