The Lupos, don't really wear out their tyres at all. So you will need to make a pit stop window type of thingy' So in a 20 lap race, the pit window is laps 8 to 12. Mandatory. I would suggest that you keep the racing soft tyres, the comfort or sports will take away some of the fun, IMHO.
I would also suggest that you have a vote on the cars, or put together a list of suggested cars to use. I enjoy the Lupos, but if i had a choice, I would definately choose the Suzuki GSX 4 or even the Elise 111RM.