Hiring a car with a tow bar

Hi all - we are considering a change of car and realise that we only need a big car when we tow a caravan.  This is usually for our main holiday and perhaps two or three minibreaks in the year.  So as an alternative we were wondering about having a small car and then hiring a car with a tow bar when we need to tow. Does anyone have any knowledge or experience of doing this?

Thanks

Ian