I have been told by FOMOCO that they do need to do a recalibration of the speedo for 18" rims. So if you do decide to put them on later your speedo will be out by a bit. The factory sunroofs are the webasto brand. As FOMOCO had delays with sunroofs back in November/December last year. City Ford (where i got my car from) were still getting the cars in with no sunroof and fitting the same brand in the car. So literally they were exactly the same. However I got mine done at factory. Make sure that your dealer does put the same model in to keep it looking original if they cant get it for you from the Factory.