Rally Co-Driving

[nobodyknows]

Hi, I've done a few hillclimbs but have been asked if I fancy trying co-driving in a rally car. I have to confess that I have only ever watched rallying on TV & never live, also never sat in a rally car much less been in one on the move.
Obviously I have a lot to find out before I make a decision, can anybody offer any hints/advice/suggestions from their own experience?
Does co-driving give enough of a thrill or will I be longing to be in the driving seat?