Passat/a4 basically the same car but obviously it's ur choice as regards styling wise.Maybe a very early e46 320d estate or a nice merc cdi estate,be about 51/02 for the merc.expect biggish miles but they do go on forever.you'd deffo get a nice 525d for the money but it may look a little old fashioned although there's loads you can do to them,would be pushing it for a 530d.volvo v70 range d5 are nice quick dervsand do the miles well,avensis estate look nice in black and pretty bombproof,they've taken a nice hit with the Toyota accelerator pedal recall!!One quick word of advice don't bother with a passat/a4 saloon if you want to put mountain bikes or stuff like that in as the boot has a very narrow angle and you'll be stripping the bike apart to fit it in!!!