Front windows basically cannot be tinted according to California law. Any glass behind the driver can be any darkness. So yes, everyone is driving around with illegal tint if they have any type of tint on the front windows.
Cops generally don't care unless they're super dark or they are already pulling you over for something and just want to tack on the tint ticket.
AW/Terra | ZSP | ZPP | ZCW | iDrive | CA
Mods: BC BR coilovers | Blacklines | M-tech rear | dual exhaust | M3 steering wheel | BMW SSK | ZHP shift knob | High-kick CF spoiler | NBT Retrofit
M3 front control arms | M3 rear guide rods | Manzo rear toe and camber links | Monroe rear shock mounts | Varrstoen ES1 19x9.5+20 Front, 19x11+25 rear