I'm in my second summer towing a 13' Scamp with a 2005 Pontiac Vibe (Matrix clone based on the Corolla platform but with a stiffer suspension)... it tows beautifully - very stable. We climbed high into the Sierras again this past month with no problems.
I AM careful to take it out of overdrive. I am also careful to keep the rpms up to help keep the tranny cool. I do my own shifting with the automatic. I pack very lightly and am careful about balancing the weight
in the trailer. I have confidence in the Toyota powertrain but I change the oil a lot and use Mobil 1. Transmission fluid shows no sign of overheating or excess wear.
I'm a pretty firm believer in sticking very close to the 55 speed limit, though I do let it creep up closer to 60 if I've got a little tailwind. I get about 24 mpg with the rig. I am very happy! The power is adequate - climbed the very steep Sherwin Grade at about 47mph at 4400 rpms... no sign of overheating... I do try to drive when it is cool and plan my trip to avoid high wind hours (common in the Mojave). I don't drive tired.
Beating my way thru So Cal traffic to get out of town, I almost got clipped by a madman hauling cars up out of the Port of Long Beach. Emergency manuevers were handled with aplomb.
My theory is that towing with a small car, I've got to be extra aware of safe towing practices and then DO THAT. oh, I have BRAKES! wouldn't tow without 'em... works for me.
to Patrick! The Scamp is great!)