I found the new Attack Pack 5-pack in the Easter train at Walmart. This one includes another release of the Bad Mudder 2, and A favorite of mine the Jack Hammer from the AcceleRacerS line. It also looks like the Motorblade has changed names to Blade Racer on the package even thought it still has Motorblade on the base of the car. Look for individual picture of each car in the 5-pack section.
In the Track Aces 5-pack it was good to see a couple of casting that have been rarely used. But the Off Track must be a favorite with someone at Mattel. This is the 15 time including variations that this model has come out.