If they haven't cashed your checks by now either they never got them or they got lost. You definitely want to call them Monday and I'd call my dealer to make sure they actually submitted my paperwork. We've seen on this site several times where the dealer did not submit the paperwork.
This! Mine was cashed with in 4 days after it arrived ( USPS delivery confirmed ). Definitely call and confirm they even have it or that it left the dealer.