Should i leave my current job to become a car salesman?

I work at Walmart where I'm severely underpaid(9.30/hour) as a grocery dept. manager. I was planning on serving my time to move into salaried management (38,000/year) but I don't know if I can put up with this place much longer. I have an offer at the local Ford dealer and they want me to start immediately and seem to strongly believe in me. I'm so torn because I've been with Walmart for almost 3 years but I can't keep waiting to make a decent amount of money. This dealer is in a reletively rural area and only has 7 or 8 salesmen, several of them I know. The general manager said his people make anywhere from 30,000 to 130,000. Any thoughts?