tow bar

Hi just need some info with the tow bar electrics , on my 1.9cdti 150 .56 plate I have a 7 pin socket with the trailer module , I’ve searched online how to add the socket for caravan for the 12v live but gets a bit complicated with different types of sockets 12n 12s etc , My question is , is...

I've recently bought an Insignia estate and need to fit a tow bar. A friend of mine has one from his old Zafira he's offered me. How can I check the compatibility of this with my car? Do they tend to use the same fixings or are they all vehicle specific? Grateful for any pointers.

Have one for sale. Vauxhall antara £40 in Leeds if anyone's interested