My best advice is get yourself a Meguairs Clay bar kit and use it with their quik detailer wax. You simply wash your car, spray the detailer on the affected area, rub with the clay compound and buff of the excess detailer with a microfibre cloth.
I decided to use the bar on my whole car, and even though I'm very regimental with my cleaning, it was pulling bits of dirt off that I couldn't even see!
You will not be dissapointed
Thanks guys
Is this stuff expensive & whee can I buy it from?
Is there anything else that may also do the job?
Cheers
I had huge tar deposits on my car, a bit of petrol on a rag worked much better than anything else, I used clay, AG Tar remover, Halfords own remover, nothing worked! Clay is ok but you will find you will have to keep going over and over the big deposits, depending on how harsh it is. Then you run the risk of seriously marring the paint work.
Tardis is a great tar remover too.
Good write up shamus.