After selecting one of the available drivers, each with their own mug shot and particular skills, you're dumped on a map of the US, and have access to the garage, the shop and individual races. The garage allows you to repair any damage to your car (for a price) and the shop allows you to purchase turbo refills and various improvements for your car - all of them are functional, no rice here. Improvements include speed boosts, a radar detector so you have warning of police chases, and various tire and brake upgrades.
To actually earn the money for these things, you need to win or place in races. There are various locations across the US, and a couple are open to you at a time. Each race has an entry fee, and it's possible to do a little side betting. In addition, the location can determine the conditions - I.e. a race in New York has icy conditions.
The races themselves are very much in the same style as F1 Race or Pole Position. Crashing into other cars doesn't cause an explosion - you just bounce backwards, lose a little speed and gain a little damage. There's various traffic on the road, and actual competitors in the race are marked with arrowheads pointing down at them as you approach and/or pass them. Occasionally, the police will chase you, trying to run you off the road, but they give up after a relatively short interval if you keep the speed up.
Two points about the racing warrant mention: One, it's very easy - I managed to finish first in four or five races while barely paying attention. Bouncing off other cars didn't seem to make a great deal of difference in speed, although it does get costly in damage repair. Two, the sound is absolutely awful. On the various option screens and title screen, there's pleasant enough music, but when you're racing, all you get is a hideous high-pitched "engine" sound that would wake the dead.
The depth added by betting on races, improving your car, and choosing different locales for races is certainly a welcome feature. Unfortunately, the racing component itself isn't particularly challenging or well done. Lamborghini American Challenge could prove to be mildly diverting, as long as you're not looking for a real "Challenge," and you turn the sound down.
