You should have a GOOD body shop look at your car and give their opinion of your problem.

GOOD advice isn's cheap, but it often is worth the price, besides, most body men will look for nothing.

There is a remote possibility that you have an incomplete lacquer paint job. Lacquer is dull when it is freshly painted, and sanding and buffing are required to bring the finish to a great shine.

Your comment about solvent is interesting.

--Enamel "cures" and has a tough coat after curing, with a softer paint under it. You do not mess with the finished product as you remove the tough coat.
--Laquer merely dries as it is solvent and pigment applied in several coats. When you want a fresh shine, you just rub the surface smooth, revealing more of the same. Until you go through the paint.

The right solvent could wash lacquer off.
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96 855R, 95 855,854, 90 744 Ti - 340,000 Volvo miles put on 7 bricks