just another thought if your car is 2000 year or newer then this should work
Find ScanGauge II OBD 2 Scanner Tool Trip Digital xgauge on eBay within, Diagnostic Tools Equipment, Garage Equipment Tools, Cars, Parts Vehicles (end time 15-Nov-07 21:15:02 GMT)
i was looking at those the other day for my fiesta 1998 mk4 as i really want the trip computer (how many miles to the gallon etc) but this does have a rev counter on it also but i emailed the seller and he reckons it wont work on my car so i wont buy one, but my searching on the internet im sure i found that EEC V ECU is obd2 compliant can anyone shed any light on this? cos i still think it will work but dont want to buy one after the seller has told me it wont.