I was just doing some math on this.
Hendrick Racing has 4 cars on Quaker State:
Jr., Johnson, Gordon, and Mears.
Childress Racing has 4 cars on Pennzoil:
Harvick, Burton, Bowyer, and Wimmer.
Gibbs Racing has 3 cars on Gibbs Oil:
Stewart, Hamlin, and Busch.
Ganassi Racing has 3 cars on Texaco:
Franchitti, Montoya, and Sorenson
Who else is using something other than Mobil 1 or Valvoline?