I blast away with the pressure spray at the do-it-yourself car wash.

 

Easiest way to keep it clean is to get it REALLY CLEAN one time (or start new), then do a 10 minutes each week in the garage with paper towels and any spray cleaner (simple green is good). It gets all the dust and dirt and keeps everything clean. Then when you want to concourse the car, get out the rubber prep stuff, waxes, toothbrush for nooks and crannies and do a spotless detail.

I spend 10 mins a week under the hood, once a month doing the wheel wells (local spray wash with a good scrubbing and a quick wash to the car), and a serious wash, and interior cleaning every 2 or 3 months.
Every six months with the clay bar, good wax and the car always looks like new!