Clear coating plastic headlights

So, Google shows a mixed bag of results. Id like to believe we've had more scientific experiences here, to lead to a better suggestion...

I have to spray base/clear on my miata in the next few weeks. Sonce I'll have matrix clear in the gun already, im thinking about spraying clear on polished headlight housings for the miata and the wife's minivan since lenses/housings/etc are not cheap. These are all 20ish year ild parts, that have been yellowed and sanded and polished back to clear. 

Ive heard this is great, ive heard this is worse than a ride through a woodchipper feet first. 

Whats the deal? Best practices? Should i? Should i do everything in the fleet while i have the gun loaded, including taillights?

Bro has been using 2K bombs (with the catalyst In the bottom) with great results. Hes done 4 or 5 pairs. Anything will last longer than raw plastic.

I've had good luck with a 50/50 mix of spar urethane and mineral spirits. It needs to redone after a few years but it works great.

Wet sand with 600 to remove oxidation, then 1200 and finally 2500. I "brush" the mix on with one of those blue shop towels. Fold it up and dunk it, brush the whole width, working top to bottom.

The mix will fill the fine 2500 scratches, they will be invisible. This light was really cloudy before.

Does it start to flake, making for a bigger problem for future me?

Not the exact help you asked for, but some info:

I tried the shake and shoot gloss clear for plastics from Krylon. Maybe due to the fact that I did it in the sun, maybe layed it on too thick. but it cracked shortly after application. Do not recommend.

A friend swears by Ceracoat (Seracoat?). I have no experience, but he hates expending effort, and his results are excellent.

I got the Sylvania kit based on this review by project farm and holding up fine in mine and wife's car. Next time though I'm tempted to get a rattle can 2K and use that to clear.

Rattle can 2k clear has been great for me. I've done a couple sets with very good results. Wet sand to remove all the oxidation ( I started at 600 and went to 1500), thoroughly clean and dry them, bomb with the rattle can.

Only one set has had an issue, but I think I didn't get it clean enough. Getting a little clear coat peeling on the drivers side headlight on my daily, while the passenger side still looks great after 3 years.

When I first got the BRZ, I had him PPF the headlights along with the front bumper. Once you get them looking good I'd look into PPF. 

I picked up a Boxster recently with hazy headlights.  I ordered yellow lamin-x film for them.  The haziness is gone.  This was pretty recent, so I can't speak on the longevity.  
* I did zero prep, other than washing them. 

In the Good Old Days, you had a headlight go out and you bought another one and replaced it for under $10.

What the heck prompted them to go to headlights that periodically fog up and cost hundreds of dollars to replace?  Sometimes older is better. 

I used to sell Cibie lights and we had a Reglascope to align them and they lasted for years and you just replaced the bulb inside if they burned out.  Today we have brighter than the law allows lights, poorly aimed, blinding oncoming traffic plus this cost factor to keep them working half decently.  I guess old tech is sometimes better than new, although it probably isn't tech that is driving this, but style.

In reply to wspohn :

Going from glass to plastic? 

Dusterbd13 said:

Does it start to flake, making for a bigger problem for future me?

I've never had peeling issues, it just clouds again after a few years. I've done my daughters Grand Cherokee a couple times. Just do the same process.

I found the idea on a truck forum years ago. There was a multi-year, 1000's of posts thread that showed how it worked for people and how it aged.

I am more of a sand and polish guy. Spent too much time sanding yellowed clear off to have a positive outlook on this. 

I sand up to 2000 and rattle can rustoleum clear.  No flaking on mine, but I did sell that truck about 3 years after I did the headlights.