some advice on a space saver for our 2007 3 series M-Sport please :) The one we are looking at on Ebay has the details 115/90/16 (300Bx16H2,IS32). Our tyre has the details 255/35ZR18 on the side. I'm assuming the 16 and 18 are the alloy wheel size so important or not?? :wacko:The auction advertises for most E90 models so isn't totally committal for a noob like me. 1000 thanks in advance, John. :)