When I bought my (former) Nissan the dealer said "free car washes for life!". They have an automatic wash at the back of the dealership and you just drive through it. I figure life is "life" and what do they care if I still own that car or not, they got theirs already. So I use it every single time I am in town. Often I go through on my way into town and on my way home.
I especially like going there all muddy. On those days I usually spray off the undercarriage at a car wash first, then go through twice in a row.
To answer your actual question, before the free washes I would usually hand wash the truck at home once a month or so with dish soap and a brush on a pole to keep the encrusted dirt at bay. I wouldn't use the automatic car wash at all but it's there and it's free.
I do not, nor have I ever in my life, waxed a car. I don't give a shit about detail work, just having it sorta clean so I'm not dragging shit inside it.
Edit:
Damn after reading the whole thread I must be the most lackadaisical sum***** on this forum. No wax, automated car wash 98% of the time... wow. I bought it to use it and don't really care how the outside looks, scratches, rust, dirt, dents, it's all character. I am OCD about keeping the inside clean though. I hate dirty living space.
Fellow / lifelong Ohioan here. Yo.
There is a school of thought that says that washing the undercarriage frequently through the winter is actually bad and tends to let the salt be MORE corrosive to the frame and other bits down there. I don't have a scientific study to confirm or deny it but something to consider before you go blasting under there with a power washer once a week in January.
