There is a 25% excise tax for bringing a car into PR. The value is based on the invoice on a new car or a value set by PR on a used one. There is a website to get the appraisal and tax estimate .
Shipping is in the range of $1000 from NY, $700 from Fla. The dance goes something like this:
0. Get a PR car insurance policy. Ship car.
1. Shipper notifies you that the car is in port in San Juan
2. You go to the port with documents from the shipper and lots of IDs. Bring your Social Security Card (weird but they want it.)
3. At the port, first, go to the shipping office then the tax office (Same building in Port). Get tax papers.
4. Go from port to Hacienda tax office downtown and pay the tax. Some say bring cash, but I recently paid with a Master Card.
5. Go back to port and pick up the car, they give you a temp plate.
6. Go to an inspection place (at many gas stations). Get the inspection,
7. Goto DMV - PR DMV competes with those in any country. Tip - be there before they open in the A.M.. They hand out appointment tickets and cut off the line when they have all they can handle that day. Tickets are gone very early.  Wait in line - could be several hours. If you ask, they will give you an estimate of what time your number may come up, so you can go away and come back at some risk.
8. Get your plates and drive off.
9. Stop at the nearest toll plaza and get a toll pass kit (toll passes are essential) complete the registration online.
See- it is simple.
