ok i try this mod today and as the tint dry, it started to crack
why is this i clean it but i think since i dint see the step to sand the light i think thats why it started to hair line crack

 

if it cracks - it means it wasnt cleaned properly before hand perhaps - or there was some sort of foreign stuff on it to cause it to crack like that. Dont spray in large coats - do very small coatings, it will help it not to crack.



If you need to fix this - get some 1500 grit, and 2200 grit wet/dry sandpaper.. a bottle of water, or a tub of water - wet sand them, and get some polish for them and get it ploshed up - then try it again - should only take about 15-20 minutes to get them wetsanded and polished up. That will clear the old tint off, and let you have a clean surface for another set of coats