One thing that I did change on them was the roofs. The way the cars are constructed, the roof is in two halves, which leaves an unsightly line across the centre, where they meet. I got round this by adding a spare roof section to each car from the Mayhem Police set, which comes with lots of different numbered roofs for your patrol cars. I had to trim them a bit to fit but once in place they look fine. In honour of being the first two police cars that I made I numbered them 01 and 02.