Autosmart G101
Cheap and very effective. Can be diluted with water and will last you ages and ages.
Perfect for wheels, arches, engine bays etc.. etc.. etc...
To remove the tar a dedicated tar remover is easiest - Speak to Hou on here, i'm sure he'll sort something out for you. Autobrite do a very good one which im sure he sells. There is also Autosmart Tardis which is decent.
Alternatively, if you have any white spirit, dab that onto a cloth and rub the tar, just make sure you test it on an area of your wheels to make sure it won't stain/cause problems then give it a VERY good rinse afterwards.