I've noticed that there are different types of knobs on the tops of 328 gear shifters. I prefer the solid silver, though most I've seen are either black or black with the gear numbers. Are the shifters/knobs particular to a given year, or can I replace the black ones with the silver easily? Also, is there any problem changing floor mats in a 328 or is there a certain kind for each year? I've seen a variety, but I prefer the ones with the stallion, not the Ferrari letters. If it is ok to replace them, are there any other favorites and advice on where to find them? Thanks.