The VW headunits have preset car-specific eqs in them that do a remarkably good job of flattening the response, although he will want to ensure that he gets a unit from a Jetta, or have some means of changing it (VAG-COM). They also match the interior really well - simple low-key styling, with dash-matched lighting. Plus it shouldn't be too expensive to pick one up, and it should be relatively theft-proof.