Any thoughts on the differences between the available cold air kits for MS3's? Any tangible seat of the pants difference? Milage improvements? I've found no difference in performance or milage after replacing the stock filter with a stock replacement K & N unit and would like to avoid a similar expe...

Any issue's with moving up to 225/40-18's on the stock 18X7 rims? I'd like to take advantage of lower pricing and selection compared to the stock 215X40-18's. I assume the 2.2% increase in overall tire diameter is within the acceptable range for computer functions. Warranty concern at all?