When you come to use your trailer for the first time on your BMW, you could have a problem. If the electrical plug adaptor as required on a BMW's isn't there.Its even worse when your dealer and customer services say, its supposed to be there in the boot in it's specific cutout in the moulding above the spare "and its not" you are than told to late to claim now.Even when I protested,I haven't had flat or even lifted the lid in the boot, you should have checked.Go and buy a new one. Yes "For something you don't even know you need. "Ridiculous BAD FORM BMW R500 Later