Okay, so here it is. I think the front sensors are protruding enough. The inside edge is maybe a tenth of an inch out from flush. It was weird with the alignment. I redid it a couple times because it really looked like they were pointing inwards and I didn't want the LI to be crosseyed. But I finally took a yardstick, squared it against various parts of the car and aligned the heads with that. I think it's an optical illusion that makes them look like their pointing in a bit.
The rear was tricky and I'm not convinced that 3M tape will hold even though I prepped the heck out of it. It doesn't look so stealthy against the microfiber cloth covering the plate but against the black frame they're not that noticable unless you're standing over them.
My installer had some trouble with mounting them under the TL's because of the curvature of the car but if it doesn't test well I'll move them. I do have Veil on the TL's so that should help but I guess I really won't know until I get it tested.
About that 3M tape: the installer wanted to do it this way and swore up and down that it would hold but I had to drive back through some rain and they began to loosen up right away. I guess it needs to set or cure or something.
The benefit of this mounting, though, was that I got to mess around with it myself when I got home. I wasn't convinced that he'd been obsessive enough about the alignment and leveling anyway so I got to do all that to my satisfaction. Only time will tell if it will hold. If not, I'll have to use the brackets.