tape all the electrical bits up, dissconnect the battery, make sure all the plugs and oil cap and such are tight, then spray like mad with loads of de-greaser and leave, and really much parets, i.e the gear-box etc, give these a brush with a stiff hand brush, then get the jetwasher and off it all comes.
i'd suggest going to the local tescos or whatever jetwash and doing it on their forecourt, i went down tot he local morrisons just after i did mine on the grass verge outside my hosue and did his there, and the more powerful jetwasher make a big difference.
no-one moaned either tbh so no mess on your drive and engine ends up cleaner with less effort...
the place round corner from where i work does steam cleaning, and on the brochuse in big underlined letters it says 'AT OWNERS RISK' so im guessing they have had a problem with this in the past...
