I have always chosen our cars. Firstly, it was because I got a company car and DH didn't, and as we were young, free and single I could choose what I liked. My criteria then were usually to do with speed and perceived status (well, I did work in advertising!)
With the arrival of DS1 it was about practicality, so 4 doors instead of two, decent amount of boot space. But still had to be a decent performance for me, as I use it a lot for motorway driving, so large engine and good top speed/speed from 0-60.
By this stage, sick of people nicking bits of my cars or the car itself, I also wanted something less covetable, so went from a Golf GTi 16v to a Renault Laguna.
Next car, with arrival of DS2 was a Renault Scenic. I was very taken with the gadgetry of the car, and in particular all the little spaces and cubby holes for storage, as well as the ability to take seats out.
It was a logical progression from there to our current car, a Vauxhall Zafira. Again, a top of the range spec, to make sure that all the bells and whistles were on it - as well as electric windows and air con (pretty much standard these days) I also have an onboard trip computer (why?) and heated seats, which are fantastic in the winter.
Key reasons for choice of this car was the versatility in terms of being able to go from 5 - 7 seats, as well as the massive boot space it has.
DH just not interested in cars, and I use the car 95% of the time. When we go anywhere as a family I always drive.