Requesting Advice on What to Look For in a Used RZR4

We have decided to purchase a used RZR4, probably an 800. I was hoping to get some advice on what we should look for and possibly avoid while we are looking.

I will be buying it for my wife and 2 young sons to ride with me on trails in East Texas and Arkansas, so lots of rocks and some mud and tight trails in some cases, but usually wider trails where Jeeps can fit.

Is there a particular year or model to be avoided? Our budget is about 10-12k, so I am seeing a number of 2010-2012 800s that fit easily into that range and we will most likely buy from an individual to avoid dealer markups.

Any advice is appreciated! Thanks!