I have to recommend the well known Mr. Hobby Top Coat 501 Gloss Spray Can Clear. Itīs pretty much foolproof.
My preference is to decant and apply it with airbrush slightly thinned with Mr. Hobby blue label thinners.
It wonīt attack decals, is very resistant to running and if you have prepared your surface correctly you will have a very nice gloss after about 5-7 coats with 5 min flash between coats. Ready to be polished after curing in the dehydrator for about 24 hrs. Or air dried in room temp for about 14 days.
The thing that I find as the biggest downside of 2K clear (besides toxicity) is that once fully cured itīs pretty much impossible to completely polish out defects by hand.
Top Coat cures to a moderate hardness which makes it perfect for hand polishing.
The NSX below is painted with Tamiya X-18 and then coated with 7 coats of TC-501. Then polished with Micro gloss and Tamiya compounds. The SL has a
basecoat of TS-17 and the same procedure for the clearcoat. Sorry about the crappy pics.
