Don't use autoglym straight on top of the tar as you will just mar your paint by dragging the tar across it. You can use wd40 on it and it will soften the tar and help with the removal if you don't have a specific product for tar removal.
There are lots of different tar removal products on the...
What products are you using that you need to do it every weekend. I have a ming blue s3 and she was treated to a polish and wax about 2months ago now it's just a maintenance wash and QED to get the lustrous shine back.
I had the pleasure of using this today on the S3. The wheels were washed with Angel wax Revelation then dried and slickrims applied. Application was supper easy and then it was left to haze up then buffed off with a clean dry micro fibre cloth which was also very easy.
Here are my results...
Pre wash is a trial citrus cleaner which is a lot better & cheaper than AF citrus power@£10/lts which only does 2 cars.
Snow foam Angel wax fast foam
Car Shampoo angel wax shampoo
Quick detailer angel wax QED
Window Cleaner angel wax vision
Chamios don't use a chamois as it will mar the paint...
You could also have a look at chemical guys black light and autobrite directs cherry glaze both excellent products at hiding defects prior to lsp application.
You should contact Brodster on here for your dark angel I'm sure he has a deal running just now.
There are lots of lsp you can use after you have polished your car you could go down the sealant route with the likes of jetseal 109 or use a wax. Or if you really want you could use a sealant then wax on top of that for the extra protection.