I've been wanting to do the same thing. I think I might have gone with a bit larger tip though, they look a bit small to me (Jaguar-ish).

They look nice

Yah, that was a concern when I first put the duals on when the outlet was even further tucked under the bumper but it hasn't been a problem.

As far as the size being too small, I wouldn't mind a little bit larger but just bought these locally to see how they would look. If I find some larger ones reasonably priced, it'* an easy swap. These were fairly short too which is what I wanted to keep them under the bumper cover.