How Often Do You Detail Your Car?

Today's Question comes to us via sabbophile2, and judging by the multiple layers of Las Vegas filth and desert dust covering my poor ride, this one is wholly appropriate. To wit:

Car detailing: how much, how often, with what? Me: Zaino the whole car, once per year, occasional touch-free wash. Someday, with a garage, I'll do more.
Sadly, I'm so rough on my cars that I never bother with detailing until I'm ready to sell. Even then, I usually don't bother. However, I do get my engine detailed every 30,000 miles. Because I care. You?