Justardnck,
I advise you give a local hitch retailer a call. See if they can examine your rig to determine if something can be safely retrofitted. I did a quick search and found
Rayside Truck & Trailer in West Palm Beach. I would call them and explain your rig and concern. If they can't help, they should be able to refer you to the right people in your area.
You want to be sure you are safely setup, regardless of your towing decision. A car on a trailer does sound concerning given the combined weight of vehicle plus trailer, and also the tongue weight. A tow dolly weighs a lot less, has very little tongue weight, and can handle all front wheel drive automobiles. Tow dollies need to consider rear wheel drive, all wheel drive, and 4-wheel drive vehicles. Many are extremely finicky being towed with a drive shaft spinning. There are numerous exceptions as many of us here have researched, but you want to take your Cadi-SLS so do your research on rolling your rear wheels on the street with a tow dolly.
Another consideration is setting up your SLS for all-wheel-down towing like we do with our Jeep Liberty (see my signature picture). Again, you would need to research if that specific vehicle can be towed in that manner. Another challenge is to find the right hardware to tow that way. They would make good questions to ask the people examining your rig. They may be able to research it for you.
