Watergate Cake

1 box white cake mix
1 box pistachio pudding
1 cup oil
3 eggs
1 cup ginger ale
1/2 cup chopped nuts

ICING:
1 1/2 cups milk
3 envelopes dream whip mix
1 box pistachio pudding mix

For cake, mix all together and bake in a 9x13 inch pan at 350ºF for 40 minutes. For frosting, put milk and dream whip into bowl. Gradually add dry pudding to this and beat until stiff. Spread on cooled cake.