www.miniusa.com's car builder
So, Just for fun, I went onto the MiniCooper site (can you tell I'm in a Car mood lately?) and built my car using their flash based car builder. Worked beautifully.. except for the roof. My Mini's roof is shiny black, body, electric blue (like the one here). So, they've 'sort' of got the technology down for doing this design it yourself on a website, but not quite.