Good point - although it's worth noting that the lighter outlets are not PWM =)
As I work more with smaller, low-voltage systems - I tend to favor those parts which are small, inexpensive, and unlikely to blow up in my face when prototyping *grin*. I can see the preference for electro caps in a larger system like a vehicle.
LOL, yeah, I've had a few pop on me, all that stringy crap all over the place.
I had a scare a while back, I was proto'ing a PIC based HV generator, was supposed to cap off at about 250 volts, so I power up, watching the DVM, 100, 200, 300, (oh sh*t), 400, (OH SH*T) 450.....all this happened in about 1.5 seconds, faster than the refresh rate of the DVM. My caps were rated at 300, that would have been a nasty *POW* if they would have let go.....
OK, back on topic, to the OP, nice work. I did the same thing for my Harley.