This may be the wrong place to post this but there seems lot's of car related problems on here. My wife's Golf has a rear panel that has gone white and chalky. The rest of the car is still shiny red. If I spend and hour polishing it looks fine but a couple of weeks later the shine vanishes and it goes chalky again. Is there something better than Mer to "fix" the colour or am I looking at getting the back quarter sprayed ? We've seen a few Golfs that look like this but the car is over 10 years old so doesn't warrant an expensive spray job just something to make it look less like a heap.
rub the surface of the panel down with 800 grit wet&dry paper (careful not to rub through to the primer). spray the whole area with clear laquer, either from an aerosol or (more satisfactory) with a compressor and spray gun. leave to harden for at least 24 hours then gently rub down with 1200 grit wet&dry. (again don't rub all the way through). polish up with t-cut. the laquer will protect the paint from oxidising again.
had the same problem with my car. I used a proper compounding paste (its alike an abrasive paste) and it bought it up a treat, then i polished it with Autoglym polish. After that you must use a Wax, this will seal it and keep the colour for longer, may still need polishing once every 6 months tho. If you can get a good colour with your polishing i would be inclined to wax afterwards & see if it holds the colour better. Or... go to your local spray shop and ask for a quick respray on the bonnet. £80ish??
If you can see that all the paint is there still, T-cut is the way. Do it in small areas. Not like a polish. You keep rubbing the same area until the T-cut seems to start drying up, then keep rubbing. Wipe it off with a clean rag. Do ths in 4" spots until you finish. Then polish it. Loads of polish. Mr. HandyAndy - really