the residual on X5 is at 59 right now, i just came back from the dealer, we've picked up an 08 X5 since our 05 is up on lease.
$960/m with 4000 down does sound like a pretty crappy deal since basing on $57K price tag is not even that loaded.
For $960/m you should be looking at a $63K+ fully loaded vehicle. also don't forget you're paying $4K down, each grand buys you down about $30/m.