here is my 2 cents - -
Plan A -- I have a 2006 gas powered EZ-GO golf cart that I use at Speedweek. Sorry, it is not for rent. I paid $2,500 for it and had the rear seat installed that folds down into a flat utility surface like a pickup truck. So, it was a $3,000 package. You can stand up on the back platform and rest your elbows on the cart top roof and shoot some nice pictures. Then you can see over the crowds and cars too. Plus there is room up there for extra cameras and stuff as you shoot.
Consider what it would cost to rent one for a week, about $100 a day? If you purchased a used gas powered cart for say $2,500 and subtract the $700 estimated rental fee, then the cost would be about $1,800. Do you think you could sell the cart at the end of the week to a racing team for the $1,800. Then you would break even. You would have all week to advertize the sale of the cart.
Plan B -- When you rent a car, upgrade to a SUV that has a roof rack. On the salt, climb up on the roof to shoot those elevated pictures with a clear view. Put a rubber mat up there so you don't slip around. You probably would need the car, rather than a golf cart, to drive the miles between the starting line and the 4 or 5 mile markers for top speed views. While you drive to the next shoot location, you can enjoy that rented airconditioning.
Plan C -- Who knows, you might be able to find a gas cart for $2,000 and the rental for a week may be closer to $1,000. Then you would only have to sell it for a $1,000 and I think that would be a go for it.
The company I bought my golf cart from had a dealership in Salt Lake City, Boise and Portland. Just google used golf carts in SLC.
Bill