I was VERY close to getting some for my car, as Paul will probably tell you there is not a great deal of difference in the price of new CXN's and going for centrelocks (all things relative).
Aside from the safety issues on a road car you have to think of things like what you would do if you have a to swap over to a normal rim in the event of a punture or if you damaged a rim you wouldnt just be able to go and buy a replacement easily etc

stunning wheels though