I have a 2010 that is in the same condition. It has been in the dirt and mountains a lot and is banged up enough to where I no longer worry about another dent, or scratch. I live on a road that is pretty sloppy, when it rains and dusty when it is dry. I don't bother cleaning it, other than maybe knocking off the big stuff. I keep the truck serviced and repair any little thing that goes wrong. I only use Amsoil synthetic oil in the motor. I put helper springs on the back, for the purpose of pulling my 12-foot dump trailer and put on a new exhaust system.Every few months I think about replacing my 03 Tundra - then I look at the price of even moderately used ones and cringe.
Then I get a wild hair and go test drive one. Then I look at the shiny paint and supple leather seats and bed that is free of dents and hair and feathers and unidentifiable stains, and calculate how many minutes it will take me to rough it up. Then I go spray off the old girl and smile.
I did finally upgrade the factory stereo so that I could charge my phone and listen to it at the same time. Wish I'd have spent that 500 bucks a long time ago.
The truck runs as good as a new one, does everything that I need and will continue doing such for a lot longer. I think about a new one, every once in a while, but that urge goes away, upon checking on the price!
One other plus, is that you don't very often hear of a dented, dirty truck being stolen!