1. Is the hitch properly attached to the car? Bolted to structural steel is preferred (if the car has any??). Structural aluminum at second best.
YES. I installed a Curt hitch designed specifically for my model. Rated at 2000# towing and 200# tongue weight. The base Corvette has a full steel frame (Z06 is aluminum). Hitch bolts to the steel frame in 4 spots.
2. Is the rear suspension squished? That can be rectified with suspension upgrades, but you don't want to upset the balance of the car, it will make steering less responsive, sometime to the point of massive understeer.
The total trailer GVW loaded with all the gear is 1000# and has 100# tongue weight due to the positioning of the bike. Measured the fender lip before and after and there is zero squish with 100 pounds added.
3. When braking, does the trailer noticeably push the car around? Do you have to correct with the steering wheel?
I road tested after I loaded it up. Stomped on brakes at 50mph...trailer stayed true behind the car. Did some hard braking while making turns with no evidence of the trailer trying to push the car around. Was surprised it handled so well. No sway...no corrections required.
4. At freeway speeds does the trailer buffet the car around, again look for having to correct with the steering wheel.
Haven't tested it on the freeway yet. We will see. Tire speed recommendation is max 55mph even though many do 70 without any tire or bearing troubles. They are only 12" wheels which is a minus for this cheapie Harbor Freight. Otherwise good trailer.