[cocobolo]

I don't have much Chevy wood experience but in another life I a few wooden station wagons. The wood it's self is strong enough if you can keep the joints tight. There are probably products that could help. I bet the wooden boat guys know how to keep good wood good. I want to keep some wood in my roadster. I have a friend here that owns a custom cabinet shop with a CNC machine.

Funny you should mention boat guys.  I spent too much time working on old - and new - wooden boats.  Here's my opinion on how to make wood last.
It isn't what you do to it so much, but what you use in the first place.  Being from the west coast of Canada, we routinely use woods like western red cedar and yellow cedar.  They are nowhere near the same, even though they are both cedars.  Red is strong, takes beautiful curves easily, very light, easy to work, takes a good finish, but dents fairly easily.  Yellow, OTOH, is nearly twice the weight, obviously considerably harder, carves magnificently, is notoriously hard on sawblades, but has terrific resistance to rot, even more so than red.  However, none of this means much relative to the old Chevy's, as they used both ash and oak.  Frankly, I see no reason that both the cedars could not be made use of in specific areas to which they might be suited.
Coincidentally, this afternoon I went to see a hardwood supplier to inquire about their supply of both ash and oak as I will need to be re-doing the wood in the '35 very soon.  Both are available in a good quality at $5.50/bf.  That's a decent price up here (western Canada) as far as I'm concerned.
What I plan on doing is probably different from most other woodworkers.  I'm very familiar with laminating wood, and therefore I expect to rip a whole pile of wood into - say - 1/4" strips, which will take a bend very easily, and then glue them up onto a mould.  In that way I will be able to make any shape I need, and if necessary I can even use the body to clamp the wood to while setting up.
Now, as to the longevity of this wood I will most likely give each piece a treatment with clear preservative.  Once glued up and shaped, I expect to add a coat or two of clear epoxy.  The effect will be that the wood will not warp or twist and should last at least as long as the rest of the car.
As for where red cedar might be appropriate, I'm considering using red cedar for the roof infill.  I would need a stiffer framework for it, so that would be ash most likely.  Then I expect to cut some 3/8" thick red cedar strips perhaps 1 1/2" or so wide, rout the edges bead and cove style, and glue the whole shebang together.  The newer polyurethane finishes are UV resistant, and several coats of the stuff are close to bulletproof.  That should do it.

[madmike3434]

Its my understanding from doing research on the net and boat guys, they seem to prefer EPIFANES VARNISH from Holland.  You thin it 50% on first coat, 25% on second ect with their thinner. Use a long hair brush . Its around $45--50 a litre and thinner is around $18 I think.  On my 35 steel standard series roadster I am using a combination of oak and northern ash in different areas.  I have also thrown some cherry into the mix on the seatback.

mike 

[madmike3434]

examples of how the wood looks with the epifanes varnish treatment
mike