Having run the Ransomville Hangover race once and completely failing I can offer this advice:
1. Have good safety equipment. A guy got airlifted out of Ransomville after getting t-boned. Scary.
2. I had a big station wagon. I dropped about 400 pounds of garbage picked barbell weights in the back storage compartment. Didn't help. Made it about 1.5 laps in the quagmire. In hindsight what I would do if I had a rear wheel drive car is to install a boat gas tank as my primary gas tank. Then fill up the original gas tank with water or sand. Fill the spare tire with water or sand, rocks, etc.
3. Front wheel drive cars seemed to be way better.
Win if you can. Lose if you must. But always cheat.