Never used them in a car, too expensive for me. But I made some home speakers with their 8" dual-voice coil woofers (8N401-DBE ?) and they were absolutely great. Made some small towers, ported design, and used a unique cross-over design that crossed-over the second voice coil at lower frequencies only. So above 80 Hz they were 8-ohm speakers, but went to 4-ohm below that, and the second voice coil worked to provide extended bass response. They were essentially flat to 40 Hz, which is pretty good for a single 8".

The problem was they sounded so good we played them too loud for too long, and after about 8 years, and coming unglued for the second time, I had to give up on them. Too bad. Now I'm waiting to build the replacements with 12" dynaudios, 3" morel mids, and MB titanium tweets. Cool.

 

Eventhough utopia is the top of the line model,
Focal Polykevlar 165 k3 is way better in my opinion.
You can't go wrong with either one.

 

I'm currently running the Utopia myself, however, I have to agree I don't think you can go wrong with any of the Focal products!