[Kiernan]

Looks to me like both cars have xenons, but the 'short' bar is just the parking lights (i.e. the ignition is not on). When the ignition is on/engine running, the full bar lights up. Only reason I know is that last week I was checking my new car and for a while thought I'd been given defective rear lights. It was only when I checked with the ignition on that the full length lit up.

As far as I know, non xenon cars don't have light strips at all, just an old fashioned bulb and they look a bit rubbish in comparison.