Tardis is better and much better value for money!
tardis £20 for 5l
AG £5 for 325ml
Thats the only way to do it imoDO AG the lazy way. Squirt it along the car, wait ten mins, and watch the tar melt off. Just make sure you do it in a cool place, as you dont want it drying on. Then i'd re wash the car and SRP