Chust to tie up this topic, since it's been touched on in a couple of other threads. Should anyone wish to go this route for their 2CV sound system - ie: use a self-contained 2.1 speaker system (ie: 2 compact stereo speakers and a sub-woofer with built-in amp), then the ones than I know of which are 12V powered are various models from the 'Creative' make:

Creative I - TRIGUE 3330 (yummy 3 little speakers in each pod...!)

Creative Inspire 5300 (actually has 5 satellite speakers, but you only need to use two...)

Creative Inspire 6700 (-ditto- 6 speakers...) I'm assuming this is also 12V since it's so similar...

And, no doubt, others.

Also, all of these have remote controls for volume, balance and possibly more. (The I-Trigue L3800 even has a wireless remote control, although you'd be pushed to find one at a good price!)

And they sound - goooood.

You can usually pick up a complete set on eBay for around £15, and often much less. Postage will tend to add a similar amount to that, so wait until a set comes up locally!

All you need to complete your ICE is an MP3 player, pocket radio, fancy phone with MP3 or whatever.... No obvious music system is on display, so it's more anti-toerag.