I had a Carlton a few years ago, although in 2.6 guise. The 2.0ltr is the same engine as fitted to the Cavalier and so engine and 'box were generally bullet proof. Since the last Carltons were made in '94 the car your looking at must be at least 11years old, which in itself isn't a problem but have a good check of all the electrics since they are prone to engine management problems, and have a good look underneath as the rear chassis legs tend to rot in spectacular style. As for it's prowess as a towcar, the 2.6 pulled a Lunar Delta 610 easily and I'm fairly sure the 2.0 would too.