What do you guys think of rustproof spraying the bottom of the car, also you can get a better package that they spray inside doors ,rocker panels etc.Good idea or what?

GM has for years been using a good zinc oxide (I think) mix in their primer. This is part of the reason their paint wouldn't stick well starting around 88

My experience has been with a GM you don't need rust proofing...although it'* not going to hurt if you want to do it.

In Canada here everything rusts and Im pretty anal about that, cant stand to see break lines and tranny lines rusting , welds etc , salty , sandy winters I think ill get er done.Thanks

Off to rustproofing you go then.

In some cases rustproofing can create more problems if not done properly, and reapplied at the recommended intervals. Where it is applied has to be spotlessly clean and dry or moisture pockets will build up. That will allow more water and salt to enter and cause it to rust even more quickly. They'll also suggest that it be reapplied after a while to touch up where stones and other things have broken through. Follow that recommendation or it will again trap moisture.

It'* been years, but I had it done on an '89 *-15 Jimmy - the total package - undercoating, door and interior panels, etc. My neighbor liked the vehicle so he bought one, too. He did not have any rustproofing done. We each had rusting in the same spots. Also, when I had to take the door apart to do some work on it, I found the appication was quite hit and miss. It is possible that they've improved since then, but my recommendation would be to save your money.

Some, who feel as you do, clean up the rust and then appy a light coating of oil in the offending spots. You'll have to keep up with that too but is something you can do yourself and costs a lot less.

My dealer put a "new" ? kind of rustproofing on my car right after I bought it(extra) I'ts a light brown Waxy translucent substance and they even shot it deep into hinge area and inside all the door drain holes. Looks alot better than the black stuff.

I've only had one professional rustproofing job in my life and that car rusted worse than any car I have ever owned. She rusted out starting with the holes that the dudes drilled in my frame to apply the goop!

I've owned 2 Bonnevilles now, I kept my first one 11 years here in Ohio and no rusting at all!
And we get a fair amount of salt.

gm4life has his done... ask him

You guys are putting up a good argument, maybe for now Ill do it on my own.thanks

If you do, you know we want a thread with detailed instructions and pics