There is a sub under the seat but there seems to be a couple of versions of the system and I'm not wholly sure which is which, the UK get one as standard which if you believe the blurb is slightly less powerful than the EU one which they pay for. tbh its a good sounding system for a 'freebie'. I'll dig round and see if I can find the post with the specs in.

Edit

Here we go

It is standard no matter which seats you have, and it just under the drivers seat. The point of an amp is it boosts the output of the stereo to all speakers. Although to be honest I'm in the same boat computers are more my thang.

iirc the amp is in the boot, it is a seperate unit. Its a tiny car and the system appears to be tuned more for clarity rther than outright eardrum bursting bass. Its a good system I would prob pay for it if was an option (we have its non-branded sister in our panda so I had a preview) although you obviously could get better by purchasing speakers, head units etc. but its good enough not to bother if its not what you are seriously into.