Back when I worked priviate EMS fulltime, my regular partner (PaRescueEMT

) and I saw a truck that wasn't being used often and asked if we could be assigned it. Almost all of the rigs (All of the BLS ones and some of the ALS ones) were Type II's. It was a unit that had been assigned to a permant crew at an old base that was closed a few years previously. All the patient compartments had been tinted (with the PepBoys Do-It-Yourself Tint Kit). The AC and Heat both worked OK in front and in back, and it was in decent shape. We requested to be permanantly assigned that unit, and then we came in on a holiday afternoon for a few hours (on our own time) and cleaned out the truck, repaired a shelf in the back, and totally restocked it. For the last few months with the company, we had our OWN vehicle and were mostly happy with it... it made life much more tolerable that we had a good truck - even if it was a POS in the grand scheme of things. Had we both stayed with the company, it was possible that we would be assigned a brand new vehicle down the road, because we proved that we could take pride in our vehicle.
Another anecdote - When I was in Louisana for huricane relief back in 2005... we were operating old reserve units from several of our companies operations... These were vehicles that we weren't going to ever see again after we left LA, and we weren't always in the same vehicle. One of the things I did EVERY time we gassed up at a state-owned truck fuelling station was to use one of the 2 self-serve car-wash bays and wash the vehicle. The first time I did it, I paid out of my pocket, it cost less than $2... the next day, the Fish and Game Officer watching the gas pumps had tokens for the car wash.
Why did I wash the vehice?
First reason - That region has these nasty, dumb bugs that come around every year towards the end of summer... they like to hang in the air and get hit by cars... we went through cases of windshield washer fluid those 2 weeks. I couldn't see out of the windshield and the truck looked like crap.
Second Reason - I take some pride (at least I did take some pride

) in my company, and a clean truck just looks better.
Third Reason - Some of our missions had our vehicles driving through flood waters... keeping the vehicles clean was good for everyones health.
Anyway - a clean unit is good for your morale and makes a good impression on your community / your customers. Even if the boss is a **** about getting you to clean the vehicle... do it. It would be even cooler if he loaned you the vehicle and he DIDN'T ask for you to wash it... then you should wash it anyway.