the registration office asked me to get a letter of approval on size from BMW dealer.. i emailed him.. and he said.. this size is not approved on ur vehicle... i checked the manual... and it doesnt mention the 20" size as an option.. it mention only 19".. .. i checked the manual for X5 2004 and up.. and i find the 20" size mention in the list of option wheels...they are requiring that the the wheel size be changed in the vehicle registration office to update ur car license...
wht a luck...