I soon retro-fitted a fuel computer.

I was lucky as it was plug and play, the wiring was already there. I didn't bother with the washer bottle though as I top the fluid up every week. Pics below can act as a partial guide on doing this really cheap modification. All I bought was the computer, the stalk and the temp sensor.

You can get a washer bottle with a float switch in it and a modified instrument surround. I butchered the cubby hole surround.





Cardboard template


Bit of hot melt glue!




If you have this wire (for the stalk) it is plug and play (along with the computer plug itself)


Computer plug




Note that the computer was only fitted to petrol cars (as far as I know) but works fine on the TDDI. You can calibrate it so it is very accurate. The only downside is the range can be slightly off as the Diesel fuel tank is less than the petrol tank capacity.