Simple maintenance will go a long way especially if you park your car on the street and not in a garage. Just like oil changes, you have to do it or eventually your engine will seize.

After working at a car wash for almost a year I picked up a lot of pointers and ways of detailing a car easier and quicker. The biggest arm saver of course was a random orbital buffer (don't get a rotary one or you can burn your paint). Almost cuts the time in 1/2 for polish, buffer and waxing your car. Takes me about 2 hours to do my EG, about 2-3 hours on my wife's Odyssey. I do that once a year or so.

The other thing is to get containments off the car as soon as it happens (ie: bird poop, bug splatter) cause that will stain or embed itself into your paint.

The last thing to do if you don't have time is to just rinse the car down once or twice a week to get salt and dirt off the car if you don't have time to actually wash your car. To give you an idea I rinse my car and van about once a week whether it be a quick run through a car wash or garden hose.

The other thing you can do is hire a guy like me to detail your car. Just started my own detailing business last month