I don't really think it's about what sort of weight your towing....it's about the strength of your tow rope and the amount of torque of the car towing the other car.
We've towed a big Hilux with a little 1300 corolla but you can't go up a hill since the little bugger will blow the clutch since there's not enough powa or torque to tow it at an angle.
just because a car can physically move something it doesnt mean its safe!!
for some thing like a celica the factory rating is likely to be only 750kg unbraked and 1000kg braked. not alot. celicas arnt built as tow vehicles!!