[twobjshelbys]

Try standing a 2x4 on edge - that's 3-1/2 inches. Run it under the car. (If you can find a way, drive over it - I built up a batch of 3 or 4. You need to be able to drive over it and not scrape anything.) That's the minimum height you need to clear *most* speed bumps. It's a little too low for some things.