Is buying parts allowed? Or do you run stock cars?
You can get gold in all the bronze class races with stock cars. Woodland Mayhem is the only race that gives me any trouble.. Frank Benton in his Grinder and Sue O'Neill in her Blockhead are the troublesome ones, really.
Silver class is where I start buying parts. I try to keep it minimal just to see how much I can squeeze out of my car; there's something fun in that.
And when gold class rolls around I fully upgrade for the last few races, the Bay Challenge and Finchley Challenge and Gravel Supersmash because those are silly hard.
Basically I like to make the most out of the least. It's sporting, it's harrowing, and it's fun. And I don't know if anyone has ever won all the races in a Bronze class car, except for the Bullet.