Yeah, ebay or ask in the 'wanted' section on here.
For removing tar you need clay. Meguires Clay with quick detail spray is probably your best bet and easiest to get hold of. It's about 10-12 quid in halfords and most decent motor spares place. You need to wash the car first, then rinse it off, the while keeping the car lubricated with either the quick detail spray or some car shampoo and water in a spray bottle, work about a third of the clay (that you have made warm and soft in your hand) around the body work, a kneeding technique works well. dry when done with a microfibre towel. You're best doing little bits at a time. i.e. do half the bonnet with clay and then dry it, do the other half, dry it and so on.