Ya I know, it sounds ridiculous but I've been googling this for a couple of hours and every single spec I find for a UK Vitara says 1500 lbs towing without trailer brakes and 4000 lbs with tralier brakes. Am I missing something?
No, that makes sense - in a way.
Stopping is the biggest safety issue. Many vehicles pull a trailers much heavier than the vehicle itself. The problem becomes being able to stop it in a sure distance. The Trackers/Vits have a solid rotor (not ventilated) so under load it will be prone to overheat, fade, warp and all kinds of other nastiness. With trailer brakes the trailer does some of its own stopping work, putting the braking force on the tow vehicle back to the level it has under the rating for a trailer with no brakes.
I'd say you'll have a hard time finding a light weight trailer (under 2500lb) with brakes.
All that said, there are basically two things to look at;
1. Towing capacity
2. Tongue weight
Even if the specs say you can pull 4000lbs with the Vit, I wouldn't. The vehicle is just GROSSLY underpowered for that load. You'll never get over 40 mph and your mileage will be cut by two-thirds. I could pull my fifthwheel weighing 8000lbs with my full-size Chevy and get WAY better mileage!
Also, when you get heavier in trailer, you get heavier in tongue weight. You really have to watch this if you enjoy steering! With the short wheelbase and VERY short distance from axle to hitch, you're going to get bounced around real easily.
It's a matter of the right tool for the job. If you've got a heavy camper, tow it with something capable. If you want to camp with the Vitara, compromise on the camper.
You'll enjoy life more... and possibly longer!