Sorry about that. In this case I can either tell you what you'd like to hear, or what is true, at least as I understand it.
Your husband will be pleased to hear that my advice to you is the same as his. Not only is that in all likelihood the best course of action financially, it is doubtful that you could ship the car anyway. To ship it, you must either hold the title or have written permission from the lender. Considering your negative position on the loan, I'd be surprised if they let you ship the Jeep where repossession would be cost-prohibitive.
My suspicion is that the purpose of the high import tax on vehicles is to protect the local auto dealers. Seems to do the job quite well. No, you won't find the same Jeep at the same price, but the same Jeep will cost less than what you paid plus the shipping and import tax. So let's say you've got a 2019 Wrangler, which cost $30,000. Add to that the $10,000 in shipping/taxes/miscellaneous, so to get it on the island you've paid $40,000. The same Wrangler costs $37,500 in PR. That's a good deal. Frustrating, no?
The cost of shipping most goods to PR makes it a bad idea as far as the finances go. It is similarly much cheaper to buy household goods once you are on the island. I would ship only those items that are precious to you.
My wife likes to think of this as our opportunity to "de-clutter" and live more simply. Eh, I smile, and try to keep the wife happy.
Best of luck!