Jim,
I hate to rain on the parade, but from my experience, I would sell it in the US and bring the money here without a question. IF you have experience or have a good Dominican friend who is very experienced with Dominican customs it might be different.
That said, I don't know your case specifically, but would image you would qualify for an exemption. Please realize though that just because you don't pay taxes doesn't mean it will be faster or cheaper. In fact, you might expect the exact opposite. I waited four months for a household shipment(did not involve a vehicle). It was almost tax free, but the exemption ended up costing me more than the taxes would have been.
Also, you said it was a Chevy. I once had a US made vehicle(GMC Safari). Finding parts was difficult and expensive and it needed a lot of them. From now on, I am sticking to popular vehicles such as Toyota, Mitsubishi and Nissan. If you were to sell your truck for say, $25,000, you could in turn buy a late model Mitsubishi Montero(the most popular SUV here) and be happily getting into wrecks while your other vehicle would have been sitting on the dock sunning itself-perhaps for months.