If you want top rung (for a top rung car:biggrin
then you might want to think of brands such as Icom or GME.
Both of these manufacturers make units where the guts of the head unit are hidden away under the dash and the only thing exposed is the Mic or a teensy unit to control volume, scanning and channel selection.
If you went for these types of units, you would get the full 5watts - which in ideal conditions (and depending on your antenna setup) would give you 10-15km range.