Technically it makes sense to add more coats, as it does deepen the shine (at least it seems to on my black sedan), and since it's a hard coating that doesn't "spread" like waxes, adding additional coats is effective. You won't ever break it back into its original suspension form (unlike when you heat/wash wax), so layering works. It's totally your preference, but I've added just a tiny amount every time I wash, and it's kept me from having to do any "major" wash jobs.

G

2003.5 Black w/ Willow G35
Premium / Sport / Aero / Winter / Navi / Tint

 

Great, thanks for the input. I'll probably wait a week for this layer to cure, then add a second layer and see how it looks.