The game was horrendously frustrating for me - I recently picked this up in the bargain bin as well - until I got smart and saved enough up for the Corvette C5. (the late 90s tier 2 one)
The setup is basically to set camber, toe-in and caster(the three suspension settings all in a row there) to as far to the left as possible(minimum values). Set the steering to max stiff. Then go to the gearing and set 4th in the middle and then go three clicks to the left for each one below that. It should look like a diagonal line. 6th is all the way to the extreme right and 5th is in the middle between 4th and 6th. Put the final gearing ratio right below the "I" - about 4 or 5 clicks from the extreme left.
Ignore everything else.
*Any* transmission mod will do. *Any* nitrous will do.(set that all full to the far right at max for everything) You just need level 1 in transmission and level 1 suspension so you can physically make the mods. Leave the engine alone - it's meaningless at this point. Ignore tires, supercharger, brakes, and so on. I did get the level 3 supercharger for more fun - but it's not really required. Sounds fantastic though to have gear driven supercharger though
Stock C5
Level 1-3 transmission.
Level 1-3 suspension.
Level 1-3 nitrous.
Level 3 supercharger.(optional but hugely fun)
Tune it a bit.
What you will end up with is a highly unstable RWD rocket capable of 9 second runs without any burnout at all/weak burnout and no nitrous. I ran it for fun and it actually flipped over backwards when I hit the nitro.
You need to put the best level 1 body kit kit on it and the biggest level 1 wing on it *and* a custom CF hood and set every setting to absolute maximum to create max downforce. Then it stays on the ground with nitro. Just.
Hammer it at the start, shift through to 4th, then hit the nitro - hit 5th and 6th in rapid succession and presto - 7.9x or so quarter mile at over 200mph. I did this as soon as I unlocked tier 2 cars and still am using it at the end of the game.
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Freebie #2 -
Grip - Get the Lotus Elise. Leave it in perfectly stock condition. The one that you get from the lot actually works better than the ones you can create until you unlock level 4 mods. Other than lacking nitrous. It's cheap and a perfect grip car. I love that I can drift through corners with it even though it's not a drift car
Freebie #3 -
Drift. The best cheap drift car that I found was to buy a Cayman S and set the suspension to be as unstable and wrong as possible so that the rear end kicks out almost by looking at it.(just look at the popup help and do the opposite - like set the springs soft and the rebound rate max hard and so on) You can also use an Elise for this, though it's harder to control. What you want is mid or rear engine, RWD, and short wheelbase.
Freebie #4 -
Road - For road, you want essentially a rally racing setup. Grab an EVO or WRX and go for it. AWD is a must and good suspension is as well. I tried it with a long wheelbase RWD car and it was horrible. In fact, none of the "classic" cars that they put in the game(60s GTO and so on) are worth the bolts that their wheels are put on with. - Ignore all of them.