Anything and everything Spitfire.

Well here I am with a newly rebuilt car and wanting to keep it that way, but there seems to have been very limited past discussion on these boards as to the general subject of corrosion prevention. From what I can gather (not all from the message boards), in no particular order:
....*) Underseal is BAD because it traps water in failed areas and causes problems
....*) Waxoyl is good in box sections and cavities
....*) Stonechip forms an excellent part of a coating system
....*) Paintwork should be kept covered by a good wax coating
....*) Chrome can also benefit from the above
....*) Products such as fluid film are very useful
........... *) In areas from which waxoyl would escape and make a horrific mess in warm weather
........... *) under washers, fittings etc.

As far as my car is concerned, the chassis and body underside have both been stonechipped during re-coating, the car has been resprayed all over (2-pack system), the insides of wings, sills, doors and box sections have been waxoyled using various tempremental spraying devices (the most effective being an old window cleaner spray bottle), fluid film has been sprayed into the inside of the windscreen surround as well as under all exposed surface mounted fittings and exposed seams have been given a bead of Tetrosyl. The finishing strips on the rear wing seams have been reapplied with silicon sealant inside them, and this was also used to seal off the front edge of the windscreen frame finisher. The exterior paintwork, except underneath, has been given several coats of car wax.

What I am, for the main part, intrigued about is how to protect the underside of the car including wheel arches. When I acquired her she was undersealed which had caused problems by trapping water in some places but done a very good job in others. It has been suggested to me that the underside of the vehicle should be waxoyled but
....*) doesn't this create a vile mess when introduced to road dirt?
....*) how long does such a coating really last?
....*) does it not fail by definition in the same places as the paintwork?
So, what does people's experience suggest re. the above? Should the underside be left as bare stonechip and paint, waxoyled, undersealed and regularly maintained or is there perhaps a further option?

The other thing was with regard to wax over the 'topsides'. Do any of the "wash and wax" products actually apply a decent amount of wax coating or is one better slogging away with a bottle of car wax and a couple of cloths? Bearing in mind that the quicker and easier a job is the more likely it is to actually happen! Are there any other easy-to-use alternatives? This is of course especially relevant since the time of year when the car needs protection most is the winter when air temperatures take a long time to dry the car and daylight hours are limited.

I have tried to summarise a car bit-by-bit based on my knowlege and understanding but please feel free to broaden the discussion. I for one would be fascinated to learn what experience suggests are sensible methods of protection.

Looking forward to hearing other people's views,

Adrian