Im half concidering a "removable" sub and amp combo for the Clio, so it can be dropped when its time to go for a pootle round the countryside, but have some heavy bass (as the standard speakers are pants) while sitting in traffic on the way to work
If u get a decent 10" the box will take up hardly any space. It needs to be strapped down for safety anyways, so will not slide when ur driving gets more urgent!