We have a 375FS Gearbox. Backdoor to the kitchen stove is 19ft. Unladen weight is 11,600. GVWR is 17,000. We are usually in excess of 16,000lbs. If tanks, including fresh water (126gallons) are empty I can make the weight rating on my 3500 Dodge.
Our original ramp door supported the cars weight just fine. Our civic weighs 2035lbs, but is quite nose heavy. A more balanced 2700lbs car might not load the ramp any worse. However, we had an accident and had to replace the ramp door and frame. The new door supposedly built to factory specs is a joke and barely supports an adult walking on it. We'd have rejected the work, but of course it was done right before a whole series of important race weekends. Built by the same clowns that built the deadly spiderman rigging for Broadway. We bolted in 8 ft ramps over the door. Now its fine. Although the door is heavier and it was already heavy. We rest the ramp on axle stands and use six foot aluminum ramps at the end of the door. In a pinch we can use our race ramps scale approach ramps as well, But that is about 16ft of ramp to get a really low car in. We lowered the trailer 3 inches by using the higher holes in the spring hangers and clearancing a bit. We also installed much better front landing jacks that can raise the front of the trailer quickly to aid in loading. We also installed etrack on the floor much longer than needed, but it helps distribute the load across the floor for attachment points. Each section of track has atleast four bolts through something resembling metal underneath. However, it has to go through the 3-4" of subfloor gap. Most of the holddown strength is just coming from the 3/4" plywood floor deck itself.
The trailer living space is very comfortable. Electric bunk beds in the rear raise to the ceiling. Nice couch and dinette fold down. Lots of cabinet space and storage. Full kitchen. The seperate master bedroom has tons of storage, bathroom, vanity, shower, dresser. The bedroom is a slide out.
The high ceilings mean its a parachute towing. Its 13'3" tall. But the height means I can store tires above the car. We put etrack on the walls and use aluminum shurring beams with etrack ends to form tire racks. A bike, a second kart, a little giant ladder, a mountain unicycle are all other items that have found its way onto the racks. Along with 9 to 13 tires (2-3 sets of race tires and a 2nd trailer spare tire).
Toyhaulers are not constructed as solidly as a traditional race car trailer would be. The RV type construction seems pretty flimsy for the weight. Its certainly not confidence inspiring. We've long considered alternatives. But other than a diesel pusher motorhome and 24ft enclosed trailer costing twice as much and up as our truck and trailer combo, nothing is as comfortable. And we have the benefit of our truck at events and at home. And also the toyhaulers are often set up for serious dry camping and play. I have a 15 gallon race fuel tank. 35 gallon gen tank. 5.5K genset. 126gal of fresh water and very large black and grey tanks. They generally have larger capacities than motorhomes.