There might be a difference due to the fact that the XLR factory wheels accomodate the run flats and the SRX wheels do not. I have both an XLR (05) and an SRX (05). The SRX wheels look almost identical to the XLR wheels. Unfortunately, I don't have my XLR factory wheels to compare since I recently bought the Vogue Speedster chrome wheels and my old X:R factory wheels are at the shop (going to be returned, but just haven't picked them up yet).
I know the shop had some trouble getting the Vogue Speedster chrome wheels on the XLR with the run flats, but they were able to get them on with a little creativity.