I found this tool on a thread on the Corrado forum, downloaded it and have been playing with it for a week or so. Brilliant bit of kit, written by a classic car enthusiast to keep tabs on his car collection. Good for keeping tabs on costs and when things were last done, oil changes, spark plugs changed etc. It's a bit anal and if you put all the costs in can probably get a bit frightening but still I think its really good.
www.mygarage.org.uk (http://www.mygarage.org.uk)
I had a spreadsheet running on my old G.
Suffice to say that after selling the car for £1200 (bought for £300) I only just covered the modifying. Petrol, Tax etc was all on top