Nissan is now hosting "The Nissan Keep the Summer Rolling Service Sweepstakes", available exclusively to current Nissan owners. First let us say, it's not often an automaker makes a sweepstakes exclusive to owners. For those non-Nissan owners, we apologize that this stellar opportunity simply does not apply to you and encourage you to keep your eyes out for forthcoming sweepstakes to which you may enter. The advantage for current Nissan owners, however, is the…