If the car is stock, then you will be in Production 2.  Welcome to my parlour!
It's a good idea to stay in production class for awhile.  It keeps the costs down, and is the best way to learn.
You can download the preparation rules here: http://www.carsrally.ca/CARSRally/Default.aspx?tabid=92
You can see for yourself what can and can't be modified.  You can upgrade the suspension, add underbody protection, and reinforce suspension mounting points.  You can't touch the engine or drivetrain at all.

I am not an expert though I do recall reading about Vauxhall Chevettes being used in rallies in Retro Cars, a british publication.

That said, I googled Vauxhall Chevette Rally and found these links in short order.  I make no claims as to their usefulness however.  

http://chevetterallycar.bravehost.com/
http://www.chevettes.com/info.php

Anthony

maybe volunteering and thats about it, right now its a long term project(all summer).  It will be used as an Ice racer, and then I will see if I can drop everything back into it so we can give her a go for Rallying.  I have figured out the cat problem now, and I was planning on adding underbody protection for ice racing anways.  I was talking about the lights on the car, because with Ice racing you need to remove all the lighting systems.  So I will need to fidure out a way to set this up so after the season is over I can drop all the lights back in it, I will be able to be done I just need to figure out how.  I will be volunteering this year at the performance rallies, and driving in the navigation rallies to get some practice.  My goal as of right now is to be at the Tall pines for next year, not this year.

The Galway-Cavendish Forest Rally is a good place to start. One road in and out . . . makes it much easier for both you and your co-driver. If you volunteer to work GCFR this year, that will help a lot, too. Fun times!

Jeannie