I looked hard at some CAPA-rated assemblies when I was considering projector upgrades. Around $100 each on sale. (looked now -- $150+. Oh well...)
Meanwhile...
Most restoration failures and disappointments seem to happen when you buy a cheap kit and don't finish the job. Like any top-notch paint prep, the effort needed is a lot more than scuff and spray. Use name-brand sanding sponges (3M, Norton, etc.), starting at maybe 800 grit and progressing to 3000 grit. Each step needs to be done complete, so that the remaining scratches are no deeper than the grit of abrasive you are using. Flood rinse as you sand, to get particles out before they do more damage during sanding. Use a machine only to do the final polishing steps; it's too easy to damage the plastic by sanding with a drill or polisher.
Thoroughly clean/remove ALL polish from the plastic at the end of each step, same as you wet-sand then wash to remove all sanding debris. It's clear plastic so easy to miss, but the sanding steps are done WET, very WET.
The newly-exposed plastic needs to be protected, and polycarbonate doesn't like petro solvents at all. Find a lens clear paint or use a water-based clear spray (my favorite), applied in THIN coats per the directions.
Lens survival includes keeping petro solvent products away from the plastic. So no paint prep or finish products ever touch the lenses. No wax, paint sealant, polish, whatever, should ever contact your lenses. Penalty is dull, surface cracking and crazing, and ultimately yellowing of the acrylic surface. Pretty much what you are fighting.
If at all possible, remove the assemblies from the car for your restoration work. This allows you to do all your sanding and polishing with full access, plus it saves damage to the surrounding paint. There's no easy way to protect the paint with tape or masking paper with all the water you'll use during the wet sanding process. This is flood-with-hose, not damp-with-spray-bottle wet sanding. Removal takes less than half an hour, and all but requires a second person for at least the bumper replacement if you want to avoid damage.
The kits you see online and in parts stores are interesting, but the directions might deceive you into thinking this is a ten-minute project. If you want great results, it takes more time and care than what they print on the cardboard package.
