It's that time, I'll finally need to replace the front tires on my 451. Do I just purchase replacement tires or should I upgrade the wheels and tires? Been toying with the idea of purchasing two rear wheels and join the "4 wheel rotation" club/help with driving stability. Saying that, I am underwater on my 451 and am approaching 100k. I was driving 200mi/day for work, but that's finally! reduced to only 20mi/day. Saying that, my drive is very windy with my car driving unsteadily on the highway and sometimes not able to maintain speed. With my 451 being underwater and mileage being so high, I figure I'll be driving my smart into the ground. At this time, I'd absolutely purchase another 451. Again the question, do I "invest" in my current 451 or just maintain stock? I was looking at the Genius Darwin wheels as I can't find the Passion V2 at as low of a price. I'd move my two rear Passion V2s to the front and the Darwins to the rear, then keep one of the front Passion V2s as a spare. Sorry for the odd wording... Thoughts? Suggestions?