I wrote about this at length for my GT4 racing guide. There's lots of cars you can use, actually. It all depends on what level you want to race at and stuff. Follow the guide below if you want a closer, more exciting race. Otherwise, you'll just be bored most of the time, if you choose an overkill type of car.
Your results can vary from track to track. At some tracks, you'll have too much advantage, at others, you'll be struggling for a win. to compensate, save your game between races. If you blow its doors off and want more of a challenge, restart the game & the race on crappier N tires. Or remove some parts.
The European Classic Car League (ECCL) an interesting set of races, as long as you carefully structure the opponents that show up. Some races will rate highly...up to 3 cars will be competeing for a win along with you! Other events will wind up being boring as hell.
Conveniently, alot of the opponents that show up in this series are the same ones that show up in the 1000 miles events (see 1000 Miles section below), minus those that are American or Japanese (so no Corvettes or Nissan, Honda, or Japanese roadsters ...no Mazda Cosmo, etc).
This lack of additional cars hurts the series somewhat, as there's a lack of interesting scenarios unless you HUNT. In fact, if you don't find a good grid, this is one of GT4's suckier race-series because you'll only be fighting one other car if the AC Cobra, Jaguar E-type, or Mercedes 300SL (in that order) show up.
It's best to hunt and hunt for a good, but slower, grid. Finding the Ginetta, Lotus Elan, and Alfa Romeo GTA is best. Even tho the Ginetta is faster than these others, it usually blows its cornering, after which it catches up down the straights. Exciting stuff. Other Alfas (the Spider and the Giulia Sprint) can sometimes keep up at tighter courses. You can use the 1,000 Miles Class A rules below to race against these any of these guys.
͸ Use semi-racing stock, sports, or semi-racing suspension (depends on what you need to get your car to corner better). Cars that corner well can go stock, while cars that need the most help will need semi-racing parts.
⊸ Sports Hard (S1) tires as well. This is what the Ai are driving on. If you have too much advantage, it's possible to also use any of the N tires as well.
͸ Racing Brakes as well as whatever transmission works best (without overkill). Some cars may need full-custom gearing at some tracks, but can have stock or close gears at some others. Sports clutch & flywheel can be used in some cars to enhance shifting (if they need it).
