Without getting in to numbers you can expect a wide variety of pay plans, it all depends on the dealer. When I was at a small store (7 techs and 2 writers) I got 25% of the net but I was also the dispatcher and warranty administrator. Larger stores may pay 5% of the net with CSI and FIR bonuses as well as warranty expense numbers. I can tell you this, any pay plan based on your CSI isn't worth crap. Even if you do hit it they will just raise it the next quarter to an unreachable number.

Now with that being said get all you can get in a percentage, preferably off the gross but that rarely happens. Know what your shop grosses and nets and figure what you need from that. Also if they won't show you the entire financial statement at the close of the month, they are stealing from you in some way or another.