DO:
any visible metal part of the chassis, if theres any rust bubbling though (depending how severe) give it a scrape, a rub with the wire brush, then some rust inhibitor.... i usually then give it some thick paint (hammeright etc) before waxing over it.
boot floor, arches, brake and fuel lines (again if theres and corrosion, have it sorted first - much much mess if done after!) sills, if you get the wxoyl kit, theres a long reach tube thingy, slip this down the holes in the chassis (a few drain points along the legs) and apply liberaly.
DONT:
any contact areas such as brakes,
TIP: avoid bits where SWMBO will end up getting her white pants/crem handbag in contact with!
lights and number plates...
pretty much common sense really, if its likely to get hot, or if it needs to be clean - dont spray it!
above all do not I REPEAT DO NOT think for one second this is a nice easy clean job.....!! - have kitchen roll/newspaper on standby :lol:
the only issu i see is choosing the right application method..
there are basically 4 options:
BRUSH - get a can and slap on where you can i little tedious, and you cant get into all areas
Pressure can - not tried yet (next purchase) but in theory they work like the weedkiller sprays you get... you pump it up and off you go - round cans, and the sprayer kit. seems simple enough
jumbo sprayer - a windowlene sprayer, length of pipe and a big square can, nice theory, but i found it was forever getting bunged up and i had blisters the size of golf balls after a long session.
aerosol - i find these great for quick covering of arches etc, although they are the expensive option. they also dont give you an option of a tube for reaching down the chassis rails.
best of luck