If you are doing the "do it yourself" tint kits, LUXE is the way to go. Very good product, good videos. I did F/R side markers, rear center 3 layer decal and tail lights on all 3 of my cars. The T/A went through 2 winters and 52k miles and zero issues. No issues with the other cars either.
As VaRedeye said, flash it with a heat gun to really adhere it. Not a lot of heat but doing some will help it really stick.
Someone out there sells (or used to sell) "stealth" side markers that match the paint color but light up LED normally. IMO looks great but there were issues early on where they just stopped working.
@Heminized your markers look great. Happen to still have the info on those?