As per the Magnis Moss Warrentey Act, the presence of a aftermarcket part can not void the warrenty. The law states that the manufactuer has to prove the the after markect part in question is the cause for the failure. But the delership will say your warrenty is void, and so will Ford. Take them to court, you will win, and they'll fix your car, unless the after market part is at fault. Auto Manufactures save MILLIONS of dollars deniying warrenty claims due to after markect parts to the thousands that don;t know any better, then they do by paying a settle ment and fixing the FEW that take'em to court. JFYI
BTW, yea, I'm aware I can;'t spell or type worth shit. Who cares.
all depends on who owns the rollers, what is done to the car, how much tuning is required and so on... For me it doesn't cost much b/c of folks I know and deals I can get.. don't even know what full price would be... 100usd perhaps and up?