This BMW E46 M3 came into us at Redish Motorsport for our 'RACPanel Repair & Reinforcement Process'.
The car had 99,000 miles and was a 2003 Coupe Manual model.
It showed the common hairline crack on the Rear Axle Carrier Panel, next to the left rear mounting point.
It also showed at least 2 noticeable spot welds broken on the left side lip of the RACPanel where it meets the Wheel Arch Panel.
Once we stripped the car, we carried out our thorough degreasing process to assess the RACPanel correctly and make sure we identified all cracks and spot welds found.
We then went inside the Boot (Trunk), and Rear Seat Panel using a borescope camera to check the internal (hidden) cavity mounts of the Rear Axle Carrier Panel.
We found 1 spot weld failed/failing inside the Left Rear Cavity under the boot (trunk) floor panel.
We also found both Left Front and Right Front cavity MIG welds with hairline cracks going through them.
There is no way to access these hidden cavity area's from underneath the car, or by any BMW-workshop service instructions.
So we have to carefully cut open access panels in the boot (trunk) floor, as well as the Rear Seat Panel to repair these areas.
This in-cabin cutting/grinding/welding/painting requires extensive removal of the car's interior, along with proper protection of the remaining items like glass and dashboard and headlining etc.
Still to this day (Feb 2017) we seem to be the only company opening showing/discussing, and offering this type of in-cabin repair into our process.
Once we'd identified all the cracks and spot weld failures (or even flex) we repair those problems with a mixture of methods.
Some of these methods are basic fabrication techniques like drilling out the broken spot weld, or V-grooving a crack for better penetration, and some are processed pioneered by us and possible still unique at the moment.
Then we can finally get to the actual reinforcement work of the job, and strengthen the Rear Axle Carrier Panel's mounting points by using our Redish Motorsport V2 E46 Subframe Plate Kit.
We first developed this kit at the end of 2012 and it was a custom size and shape never seen before.
The way we carry out multi layer plug welds and interconnection sandwich-panel compressions is still what makes our process structurally ahead of others, and ultimately likely to last longer when compared to a like for like process.
There is so much to welding and the intricate affair of line up, close contact, heat affected zones, that it's a far more involved process than simply welding some metal plates to a chassis.
Once the welding and fabrication work is finished we then go to extensive levels to make sure we've prepared the Rear Axle Carrier Panel and it's overlapping panels ready for our highly regarded 'corrosion protection' stage.
We make sure no sharp metal is left, we remove localised corrosion, blow away loose dirt debris from neighbouring panels, degrease the panel(s) with panel wipe, warm the panel(s) with IR light, and only then can we apply our first coat of protection which is Etch Primer.
Once the Etch Primer has dried with IR light, we apply a 2nd coat which is High Build Primer.
We then mask and protect the wheel arch lips, rear wings, rear bumper, rear panel, boot, and any other area's of the outer painted body which could be at risk of over-spray.
We now apply our sprayable seam sealer to the underside of the car at the Rear Axle Carrier Panel, our Redish V2 Plates, and the Left Wheel Arch Lip, as well as blend out into neighbouring panels like Boot (trunk) Floor Panel, Seat Paint, and RTAB Pockets etc.
Our standard textured seam sealer is our own colour blend to replicate the factory Electrophoretic coating from when the bodyshell was 'dipped' at the factory during the production process.
Some customer opt for 'body-colour' paint finish underneath which is no problem for us as we stock approx 100% of E46 standard option colours, and almost 40% of E46 individual colours.
Now we move on to the cavity waxing which is just as important as the paint/protection process on the outside of the panels (underneath the car).
Then we can rebuild the vehicle to our exacting standards to ensure all fixings are correct and OEM, torqued, and paint marked.
We finish with a brake fluid changes and full system bleed, digital wheel alignment, and a 2 hour in-house internal/external clean using professional products and detailing techniques.
A 12 mile road test on varying roads completes our work and the car is ready to be handed back to the customer.
If you're looking for the ultimate in OCD-ness, excellent attention to detail, and the most OEM looking finish you can currently buy then please feel free to give us a call to discuss this repair.