What do you look at when buying a used trailer? It's a 2000 Exiss XT-400 gooseneck. I can look at the obvious, like the floor, tires and making sure all the lights work, but what else should you look for? I can't find a review for this model of Exiss, so have nothing to start with. I noticed the rims are rusty and the bolts on the back have surface rust. Should those be replaced?

Hello .. Welcome to the forum

This is an Exiss four horse trailer right ? The following applies to any trailer.
Floor is most important. Pull the mats out. This is a pain and a lot of work... But it's the only way to assess the floor condition. A lot of damage can happen quickly to a uncleaned horse floor. The surface rust on the wheels you're seeing is not likely a real problem in a 6 year of trailer.

Next make sure the trailer neck-over will fit your truck. Too short of a neck on a too tall truck will make the trailer travel uphill. This puts a heavy load on the back axle & tires. It's a serious fix to be in.

Then look at the welds in the back corners (Up & down) and joints. You're looking for cracks.

Tell us what you find ...

Yes, it's an Exiss 4-horse. I bought a 1996 3-horse Featherlite in '04 and had to replace the floor in '05, so I know NOW to look under the mats! Thanks for your help. I'll let you know what I see.