A Cupra with a tow bar shouldn't be the problem.
Ask Eri here in the forum. He is from the Netherlands and I think he has mounted one on his Cupra.
The actual tow bar won't be a problem. It might be the pulling of a trailer that could be a problem. The R's manual said the car shouldn't be used to tow.
Scott
your welcome to have a play.

Blimey, that's alot of car to be sat idle for 3 months mate