VW Passat (Saloon and Estate)
Impressive Fuel Economy/power balance on these:
(this is my favourite)
http://www.wisebuyers.co.uk/motoring/car-specifications/Volkswagen/Passat+(2001-05)/VW003900/ -> urban - 15km/litre, extra-urban - 25, combined 20.9 - BHP of 128Volvo:
This one seems to be quite powerful (bhp of 180) but the fuel economy ...
so this is a no no i think.