Reading the bank surveillance thread got me to thinking. What is your opinion of the worst business environment to install a surveillance system? Just by the shear openness of the business and lack of any communication my vote would be a car wash. A car wash is almost never attended and is almost always a wet environment. They will always need lens covers cleaned from overspray if you install anywhere near the bays. There is usually no way to move the cameras away from the bays to keep water and dirt off of them. Maybe install a few poles at the vacuums?
I would definitely install vandal resistant domes and conduit to each camera. Megapixels would be a definite requirement especially for forensic recording purposes. I would also try to have a camera facing a camera to protect them.
Offsite recording is best if possible. If on-site recording is the only recourse, I would suggest an armored DVR box and might even find an old computer to use as a dummy. Of course you would need a camera on the change machine but again it would be a wet location and vandal resistant. It would also be best to position it so the face and currency denomination inserted was recorded but this would be easily countered by anyone with a can of spraypaint. Do these machines support Point Of Sale?