A jet wash is a bit fierce, a gentle hosing shoud be suffice. Run some 3 in 1 oil or similar aIong the piping between sills/wheel arches and body work every 3 months or so. I grease the king pins with Castrol CL grease every 400 - 600 miles, 4 or 5 strokes of the grease gun and wipe off any surplus, whilst the car is jacked up I check the front tyres for damage and touch up any flakey underseal with some black gloop containg waxoyl.
