Chuck - a couple of the guys looked into this and concluded it would be all but impossible to isolate the huge crash bar behind the GTR rear bumper - this thread has most of the details, but there are others if you search for "parking sensor"
I went for the dealer fit ultrasonics. I know they spoil the look at the back a bit, but I figured I'd soon make it look a lot worse if I went without sensors. I don't find it easy to judge where the rear quarters of the car are when reversing, so the sensors work for me.
Or at least they do prvided it's not raining. After a very wet day on Friday, every time I selected reverse I got a solid beep from the sensors until I deselected reverse. And the beeper on this system is ear-piercingly loud. I should have known it was going to be too loud when the dealer said they could quieten it down with some sound deadening material if I found it was too loud after using it for a while. Apparently there's no vlume control on it.
Has anyone suffered similar problems in the wet? My RS4 had ultrasonics and I never had any problem at all with those. I'm wondering whether it could have been a short somewhere in the wiring with all the rain? I checked all the sensors in case some debris was covering one but they were all clear.
Next day oince dired out they were back to normal.
i got them on the back and i don't think they look bad at all - anyone considered having them on the front as well? I'm currently parking about 3 feet away from everything as I can't judge the front end at all.
I've also gone for the ultrasonic option, front and back.
They don't affect the shape or line of the car at all, I've no idea why people would even think that?
And as you correctly point out, colliding with a bollard or another vehicle is much more of an issue!
Had dealer-fitted ultrasonic ones on the rear of my RX-8 and they were an absolute godsend, wouldn't be without them now.
I'm mildly disappointed that we don't have fully integrated sensors that read into the display, like on BMWs and Audis that give a physical readout too, wonder whether this will ever become a future upgrade option?
APJ - how did you get them on the front. I was told by my HPC they couldn't fit them on the front?
And i'm with you, no idea why they'd omitted it from the standard spec using the MFD for the 'anywhere, anytime' car. Having it on the 3 series touring makes parking a doddle. Can virtually do it blind.