E46 M3 boot floor repair/reinforcement

TI-Motorsport offer a thorough and cost effective repair solution to this common issue for E46 M3s. With experience with both road and race M3s you can be sure your pride and joy is in good hands. As well as permanently repairing and reinforcing the subframe mounting points, we also provide a folder with photos along the way for your records/service history.

Here’s how our process goes

• Removal of the rear interior to make sure nothing is at risk of being damaged from welding heat etc.


• Removal of all rear suspension and drivetrain components as well as the fuel tank.


• Removal of standard underseal/seam sealers to identify cracks /areas of concern.


• Drill-stop and weld any and all cracks around the mounting points


• Welding in reinforcement plates & grinding flush


• Under sealing


• Rebuild & check/set geometry

We offer this service from £840 to £960 including VAT, depending on the severity of the cracks. While the subframe and fuel tank are out there are several common weak points that our customers often ask us to attend to. These include;

• Replacement brake hard lines (over-tank) – £150


• Yellowspeed rear camber arms fitting – £100


• Diff rebuilds with or without BMW Motorsport 3.9/4.1 final drives – POA – We keep a spare differential here, so we can have it ready to go for you to minimise down-time


• Powder-coating & re-bushing the subframe and differential – POA – We keep a spare subframe here, so we can have it ready to go for you to minimise down-time