I'm not doubting that will work but doesn't all glass cleaner remove wax? If so, don't forget to re-wax those sections after cleaning them.
That is the main reason I like my liquid paste wax method. It waxes as it cleans.
ORIGINAL: canadiancanuck
I have the best and safest product for tar, now don't laugh but this crap has been working for years, drive to your local GM/Chev dealer, purchase a can of the GM Glass Cleaner, it is safe on the finish and removes all gunk, just spray it on, let it sit for about 30 sec and then wipe, it may take a few applications but it does work without stripping the finish, this also works on 3M tape from badging/ decals etc, trust me, I have 2 cases in the garage and I use it for everything. I detailed cars for 9 years,
U.S guys - best blood/ink, oil/ grease remover for fabric/ carpet etc. is Sanifoam... it's a bathroom disinfectant, literally says on the can "kills 99.89% of bacteria, HIV, virul fungus...." < you know that shit has got to work when it can kill HIV, but it does take out 2yr old pen ink stain on a car seat.