I have a 2010 Honda Civic Lx-S and want to do tinting but i cant decide on 35% or 30% all around. Taking into considerations 28% is the legal limit for FL but i also have black interior and black exterior.

 

I always go darker. Unfortunately when they tinted the Civic they forgot that I wanted 20% and went 30%. Not nearly dark enough for me.
It's personal preference, but the difference between 30 and 35 is slight. I would go 30%. Will keep the car a little cooler in FL. Maybe even 20% on the back and rear sides and 30% on the front sides.

 

If 35% and 30% are you choices i would go with 30%