I have 50% in my front windows (done by VIP) and 35% in the rear and back windows. And during the day my front doesn't look tinted at all, and I've been thinking about getting it to 35. My only hesitation is the cop situation, but i really don't think they will pull me over since my friend has a honda civic with 20% tint and she is usually just pulled over for speeding and not her windows. I think 35% would look sick, it's still not very dark though so i don't think there will be an issue. And i drive with my front windows down all the time as well.
i'll try to post more comparison pictures