[MMM5]

I store the spare on top of the trunk floor. There are tie downs back there that line up with the center of the wheel. I used a standard ratchet strap to secure it. The kit is thin so it doesn’t occupy a lot of space. A small sacrifice imo. I was 40 miles from home on a Sunday afternoon recently and found a nail in the shoulder of my rear tire and thought I might have to change it. Thankfully the nail was tangent to the circumference of the tire and didn’t penetrate.

I offered to test these kits for modern spare and we solved fit issues with a custom spacer. Both kits have the same wheel but different spacers. On the first trial I didn’t think the 18” wheel would work for either vehicle. My x7 has 21” wheels. The spacer is nearly 1 1/2” thick so the spare wheel clears the rotors. I can’t speak for carbon brake rotors as my M5 is not a comp. Matt with modern spare was very helpful and might be able to answer that question.