Hi guys, on my racecar I have to use 13" because of the rules.
The problem is not the diameter, the problem is the design of the inside of the rim. If you want to use an original chassis (no fender flares) with a 5,5x13 asphalt cutting disc 😉 then maybe you could have a problem.
For example, I cannot use my 8x13 ATS without spacer, because the gap between rim and brake caliper is too small, better said there is no gap. Doesn't matter, the car is wide enough. But if you have a car without flares and no Touring (much wider at the rear fenders as the Limo) and you need a little spacer to get enough gap between rim and caliper, you could have a problem. I did a test yesterday for you. But I have only original Alpina 5,5x13 ET18 and no other rims in this size. But the good news, they fit to the caliper without spacer. So if you have such rims, you can use the combination with a non flared Limo. Check your rims inside what you plan to use. And let us talk again. I took also a few pictures, not good quality but had no other chance yesterday. I am sure this will help you for the first step.
I am not 100% sure but the Alpina TII Touring shown at BaT has spacers, I bet you cannot use this combination at a Limo without fender flares.