Scenario, last year I used a car cover for when the car wasn't used over winter, but, in October, I took it off to go down to Tom Hobbs for welding. Never put the cover back on and just left the car parked up.
Washed as usual over the months and never noticed anything untoward
Then, as the sun made it's appearance last week
I noticed very fine scratches on the roof
You can only see them in sunlight, normal days they disappear, so I never noticed. Don't know if they show in this pic
So I set about them with what I have in the shed
2 days by hand and then rotary, nowt, never touched them
So on Monday I ordered a Hex Logic yellow pad and some SSR-3 compound
These arrived this morning so as the sun popped out after lunch, I thought I'd try by hand first. Well, brilliant stuff
Half an hour and most of the scratches removed
Might machine the rest tomorrow, got to stretch the days somehow
Hope I haven't bored you