I used to have a white van the same as your car (a 1986 Vauxhall Astramax) , it was suprisingly able to move quite a bit of weight (tonewheel hammond's in the back) The van was worth about £250 at the time and more than once I had £28,000 of new Hammond and Leslie inside smile Everyone probably thougt it was full of copper pipes and old boilers!

But towing is different to having the weight inside the vehicle and its likely to be unstable. I am certain something will come up for you.