It would be possible yes, but not exactly sure who could do it. There would only be a tiny difference in the speedo neways, as because I have smaller tyres than the standard ones, the rolling radius is pretty much the same. As for 19's...well yeah that would be cool, but your probably looking at 215/35/19 tyres, and as I've said before - never again! As it happens I just popped out for lunch, and when parking up on my return I put full lock on and heard a small amount of scrubbing - that's with 18's and a 30mm drop...