i dont' know how much it changed, but when i got my 3, it was $500, i think the x5 and 7ers were $1000, i can't remember the 5.
cca site has the
pdf describing the loyalty rebate thing. i'm getting the adobe reader right now, so i guess i'll see.
edit: z, 3, m3 and x3 gets $500. 5, 6 and x5 gets a grand, and 7 gets $1500