Don't know if GM will increase rebates for 2013 models. In the past GM has given special incentives to dealers to get last years models off the lot.
Rather than tracking publicly announced rebates, you should consider tracking GM to dealer incentives. That is where the big savings may be. You should also be tracking all 2013 inventory of the exact model Cadillac you want. Your local dealer may not be willing to fully pass the GM to dealer incentive to you. Out of area dealers may, as they may see you as a opportunity to move last year'* Caddys off their lot.
2001 Bonneville SSEi, 219,000 miles.
Whats in my driveway:
1998 Chevy S10 4x4 ZR2, 1999 Olds Bravada, 2001 Pontiac Bonneville SSEi, 2007 Ford F-350 regular cab 2WD, 2008 BMW 335i coupe (Wife'* replacement for her Bonneville). The Bonneville is my favorite of all the cars in the driveway.