One of our other (Satin Red) Cavalier's runs on bio fuel, that's a 95/M 1.7TD GLS, with Diplomat leather, auto closure of front and rear windows, electric roof, built in full colour sat nav where the ash tray would normally go (we dont smoke), and a twin fuel tank set up with 6 port fuel switch over valve and flat plate heat exchanger. We've modified the fuel filters to ones from an Astra 1.7cdti, as they are easier and less messy to change then Cavalier ones.
This will be up for sale in the next 12mths, we're getting a Mk1 Ph1 Renualt Espace 2.1TD eventually to replace it - but we've had 'Mazzie' as she's known since Feb 2007, done around 85,000 miles in her, and we reckon, saved around £8,000 by not buying diesel for her. On that basis, we dont mind spending a few quid here and there on her come MOT time.
Our 3rd Cavalier, is my 1989 1.6L (carb), in Astro Silver (very rare), which is awaiting restoration, and has GLi interior, CD alloys, and will have electric roof, electric windows all round and an LPG conversion. She's also got the built in sat nav same as Mazzie, and we've altered a period radio cassette to have an aux input so that I can plug in an iPod or MP3 player without the car looking like its got a flash stereo that is worth nicking.