Yes ,if you are going to buy one get it with a poly tub, do not leave salt in it after spreading and wash off all metal parts and then oil them up after use make sure that rock salt has no big lumps and don't fill it all the way maybe 1/4-1/3 full
Don't forget to wash the tractor and all three point hitch parts too. A new spreader is way cheaper than your tranny case corroding.
If I spread salt, I try to shield the back of the tractor with poly and spread only one or two bags at a time. The poly spreader makes total sense. My Land Pride spreader is metal and the salt is really abrasive to the paint. (and beats the heck out of the metal too)
Also, keep your PTO speed low if you're just spreading driveway width. That spreader wants to throw it far enough to kill the lawn. Don't ask how I know this.