I have.

I own a 2007 Volvo V50 which I bought because I needed something that could hold my a baby stoller. In the Volvo V50 I own, there's no bluetooth. There's also no way to replace the car stereo, because it's integrated into the centre console, which stands a piece of obsolete aluminium art. There is no easy way to get integrated bluetooth without hacking in between the head unit and the amp, which the Volvo dealer neither knows how to do, or is willing to do.

Using the FM transmitter both to send music (instead of using a MP3 cd) and to send voice to the car radio was not as easy as having the car stereo automatically connect to the phone, but it was an great backup alternative for all the cars in the world where bluetooth is not an option.

By the way, in my previous car, I DID have bluetooth. A2DP from both the N810 and the N900 to a Pioneer DEH-P9800 was more troublesome than FM transmitting. The FM transmitter were even better sounding, since A2DP would break up.

Of course, it's not a perfect solution, it's just a fallback technology. If I could find a review gave a GPS with a DLNA renderer good reviews as a hands free and media streamer, I would use that to upgrade my Volvo. Unfortunately, as far as I can tell they're all piss when it comes to audio streaming.

I am working on a way to use the N810 as a DLNA renderer for my Android phone, but unfortunately I can't get that working as a handsfree, so I'm still out of luck.

The FM transmitter option, I would like back. That option died when my N900 took a bath. When you argue against the FM transmitter, to me it feels like arguing against including Edge technology because Super 3G is better. Well, yeah, but you can get Edge bandwidth in a lot of places where 3G receiption is spotty. You can use integrated bluetooth in a few cars but there's a lot of cars where you'd have to use some external Parrot kit, and for mine I can't even get that easily.

Oh, wait. I am a geek. Well, I am a geek outside of this group, nowadays.