Definitely the back.I tinted the back but would not tint the top. It has ample factory tint and doesn’t get hot.
I held off on the top (tinted all other parts) to see if it becomes an issue as the weather warms up. So far not an issue but as summer approaches will see if rejects enough heat. The car sitting in bright sunshine in high 70’s weather had negligible heat when feeling the glass from inside. Promising, but a big diff between high 70’s heat and 90/100 degree heat.
Isn't the back and top the same piece?
Edit: Oh, so the back is large and the top if just the little section? you're saying, do the large back but not the top?
The glass roof has a ton of tint already. I live in SoCal where it’s sunny all the time and it’s not a problem. I really would not waste money putting more tint.I am very interested in how you (and other current M3 owners) feel about the glass roof factory tint as we move into summer. I’m in Georgia and have concerns that my head will constantly feel hot under that glass roof during 90+ degree summer days. Please all of you report back occasionally on this. I won’t order until Q4 of this year so fortunately I have some time to get your feedback. Thank you in advance!
If I were to do the top sunroof, I would do it in 75. The tint is already pretty dark and as another poster mentions, you wouldn't want to darken it further--otherwise what is the point in having the glass roof? I like having light come in from the roof, makes the whole car seem more spacious.I plan on doing 70 or 80 on the windshield and 45ish on the sides and back (one piece only). I expect I'll probably do the top in 70 or 80 as well. I can't imagine it not providing some level of benefit in the Florida heat.
Tint the sides and not the back just as you said. Live with it for a while and see if you like it. You can always have the back done later. No harm done.
My experience with my X's windshield is that with that much glass, the car gets really hot. So with no tint in the back, I expect to transmit a lot of heat. that is why I did that portion (despite the cost). With regards to the top, that has dark tint already, so I left it alone.This is exactly what we've decided to do. We tinted the sides and we'll decide in September if the heat of the north Texas summer warrants tinting the back and top.
If I were to do the top sunroof, I would do it in 75. The tint is already pretty dark and as another poster mentions, you wouldn't want to darken it further--otherwise what is the point in having the glass roof? I like having light come in from the roof, makes the whole car seem more spacious.