dont have to check them. its illegal in TX.
sure lots of people get by with out a ticket for them. Dont drive anywhere around me, you'll get a ticket.
its not the fact you can see them sitting right behind them thats the problem. its the fact that in broad daylight the brake lights arent bright enough to overcome the ambient lighting and still be seen at any distance much less the 300 feet required. keep in mind the law specifically states tail lights- plainly visible to 1000 feet. and the brake lamps have to be visible in "normal" sunlight to 300 feet. tinted tail lights, when used in normal sunlight, arent visible anywhere near the required areas. plus the red rear reflectors have to be visible 100-600 feet when normal low beam headlights shine on them- again, when tinted they dont meet this requirement.
all that to say, just because you havent had a ticket YET doesnt mean its legal and the law shouldnt still apply to you. The state has had a few fatal accidents resulting from such lamps during daytime hours and I would imagine thigns will start being more aggressively enforced.