Technical Clear Urethane over lacquer ? Can it be done?

Facts incoming;

Clear lacquer requires several coats so sanding and buffing can be done.

The solvent in any material is mainly to get the material atomized and out of the gun.

The majority of lacquers don't crack and craze off, rather they melt and rinse away. Unless it's been on the car for decades cracking won't happen.

Slow dry urethane solvent will soften the cured surface of relatively fresh lacquers with no ill effects observed. Example, like 85 and up temperature rated urethane solvent will indeed soften the dried lacquer surface. If lightly sanded you can see it "melt" under the 1st coat. That's a bond.

Mix n match is so frowned upon, and yet I find that when it's 4pm on a Saturday and you're asshole deep into the job and no shops or friends around then you do what ya gotta do. If you're doing it in the 1st place you know enough not to do the totally wrong thing, like lacquer over rattle can.

There's only so many solids and solvents used for auto grade finishes. The stuff is made from common raw commodities. The solids in lacquer and urethane are nearly identical but the solvents and binders differ based on the applications. Motrin brand Ibuprofen is fuckin Ibuprofen. It isn't proprietary, so CVS brand, Advil, Motrin, Walgreens, all the same active ingredients. Paint is the same thought. Formulations and dry/cure times vary. Some brands just suck. No matter what you do they might still stick it in ya without even a kiss. Dupont Chromabase, worst tri-coat material EVER. It lifts itself and crazes before you even get to clear. Garbage as far as I'm concerned regardless of anyone wanting to say how great it is. Not me, have fun, it sucks. PPG 2021 clear? Go ahead, not me, never ever again. I'd rather bash my head into a brick wall. Self abuse, and nothing except excessive sanding time and wasted material makes it even acceptable. I've spoken on it before and again I don't care who chimes in loving so much they need a smoke after just looking at the can. Ok, that's a little extreme...maybe.

At the end of the day put your 'thane over the fresh lacquer after adequate flash. Put some solvent in the 1st coat. You'll get kool old school lacquer colors protected by a durable urethane finish. I said above, relax, it'll be ok, everyone.