What hasn't really been discussed is it may be a suspension reason why they don't want any trailer towing done.

Most newer cars with performance type suspension don't have the same suspension travel like older cars.

Adding any trailer behind a vehicle changes the way it handles, manufacturers don't want to take the risk of saying you can pull a trailer with anything less than a SUV or Truck.

Even at that, the performance versions of trucks aren't supposed to pull a trailer (Dakota R/T, Viper Ram Truck, SRT Grand Cherokee).

I put a receiver hitch on a 2000 Dakota R/T Extended Cab pickup and soon found out that it bottomed out the suspension with just the trailer behind it. Adding air bags helped, but it still wasn't an ideal setup handling wise.