i have asked the dealership to add the music interface to my original spek for the S5. Unfortunately the car is going into production next week,too late was the cry. The dealership said they have fitted these themselves to a few Q7,s.and the would be able to fit me one on the S5 when it arrived at the dealership. Should i let them loose on it ? or is there any drawbacks to being fitted on site.Would appreciate any advice.