"In this Special Series, I document my experiences with the MLT Engineering undertray for the E9x M3.
I have a feeling I know why you're here, your OEM plastic undertray has cracked and it's now hanging by threads.
In this entry, I document my installation of the aluminum skidplate. TL;DR: it was like advertised. "
It's a simple DIY.
What makes or break a DIY installation is usually the requirement for tools, followed by the complexity of the installation.
In this case, all you need is a ratchet, the right box set and you're off.
OEM plastics, be gone!
With the car on the lift, we removed the damaged BMW undertray. The issue with plastic is threads and bolt sections that easily be damaged just by taking the piece on and off.
Notice how cleanly the center section tore off? No human was involved.
This is a great example: the corner section by the fender line was gone. Zip ties it was to hold it together.
BMW traditionally uses black steel bolts for its body panels. They were rusted, of course. We threw them away knowing we had new hardware with the MLT unit.
There should't been 2x massive holes in the center section of that tray.
In with the MLT.
With the OEM undertray off, we put in the MLT unit going in reverse order. There are a few simple tricks to ease the already simple installation.
First, you want to insert the undertray over the bumper section. If you start with the oil pan skidplate bolts, you'll have a hard time even with the slotted sections.
The bumper bolts are all easily accessible. Make sure to use the washers to avoid tearing the bumper's bolt holes over time.
Make sure you slide the vertical metal tab by the corner sections inside the fender liner before firmly bolting the undertray.
We loosely bolted the oil pan skidplate bolts to allow leeway to fit the bumper holes with the threaded inserts on the undertray skidplate.
You can remove these wires if you want to. They serve no clear purpose anymore. There is a slotted tab that holds them to the chassis.
We opted to keep them on the skidplate and used washers and a nut to hold them down. In the future, you'd simply need to slide the upper section of the wire out of its chassis tab. No need to remove the nuts!
Yes, it clears.
No modifications were needed to fit the skidplate, anywhere. This also applies to clear my 1:1 GTS front lip chassis brackets that go through the bumper.
The skidplate inner section that bolts to the front bumper does not extend to the brackets. For GT4 lips, the ducts are situated to the right of the vertical bracket.
Since Winston launched his undertray in 2020, I have not seen a product that rivals the mix of simplicity, lightness, efficiency and price of the MLT unit.
Most importantly, it's made in the USA and supports an active M3 V8 owner.
I hope this help you in your decision making process to replace your damaged Genuine BMW undertray.
I can help you towards the MLT unit year long here.