I believe Tony Dean, fitted a tow bar to his Z4 - I was given a 2004 Z4 2004 2.5i SE by my brother 11 years my senior and has now had to hang up his driving boots. I like the little car so much that I decided to build myself a small teardrop trailer (one up from a tent) very light from 5 mm plywood - it weighs around two Cwt. however, when i tried to buy a tow bar no one was making them for this model of BMW, now it has a towing eye on the right of the rear of the car, and I wondered if there is one hidden on the left leg behind the plastic, (so that the car chase could be used for a left or right-hand drive car.) if so I thought I could make up a tow bracket that bolted on using the eye bolt holes to attach it when it was required and remove it when it was not in use. The trailer is virtually a tea box so it would not be putting any real strain on the eye bolts' threaded holes. Failing that where can I buy a tow bar for this model?