its pretty hard to break a windshield in a strong roofed car. that car has a very weak roof, that system is very loud indeed im sure, but my guess is still around 152-153db on a TERMlab sensor meter, the termlab db meter is much more accurate then most spl meters like the AC(audiocontrol mic). as long as the windshield is on a strong roof, there are super-street class cars hitting 165DB area not breaking windshields, lets say 32000 watts rms and 8 -15s. db drag has street classes that don't allow plexi windshields and people get the most they can out of stock glass, its more about the roof then the actual windshield.
I used to do a lot of DB Drag - back in 2002-2005 time. I had a j30 with a wall in the backseat with a 8 cube box with 2 solo-x 12s and 2 kicker 2500 amps, my best SPL was 149.2 at the dash, and around 150 at the head rest at 35hz on the termlab sensor, it was not a one hit wonder and tuned for low bass not just loud 45-50hz area. I ran super street 1-2 cause it was a wall and I was beat a lot just cause my system was more of a music system and not a one note wonder. on the audio control mic my car was around 158-160DB.
those cars that are really really loud are something to be inside. I was at a DB drag competition one time, and asked if I could sit in the truck while a 5 minute bass race final went on. I sat in a truck that had 4 18s in a camper shell truck with the rear glass removed as a cut-through and a bandpass setup with 16000 watts. it was able to do 159 db on the sensor, and was hitting 154db for 5 minutes with me in it, it was something to experience, its just insane, a whole body gasum, lol
