After lots of phone calls and "googling" I found an auto parts store that will sell me a Spare Tire 170 Type, SLK320 for $238, shipping included. They claim it will work on either the front or rear of the SRT. I have read all the threads on this forum regarding tires and although people have suggested that the spare for a 2002-03 SLK 32 AMG would work I have not heard of anyone actually buying the tire and fitting it. This price is actually $200 less than the Mercedes dealers who would "special order" the spare. All sales final is what everyone says. One Mercedes dealership mentioned they had many spares laying around and that I was welcome to visit and try them on the SRT. Maybe I should spend a day going through tire roulette...

Paulius