We own an '06 35CKQ and have had very few issues with it. I could only repeat what "retispcsi" and "kennethwooster" have posted. Carriage built their own double-box frames on site. We believe it's a very well built unit. Are their better built/expensive units? Yes, but this is still a high quality unit. The only real issue I've had with the trailer was the Tow-Max tires that came on it. I've known other owners of the same year trailer that had some pretty damaging failures with those tires. I didn't take a chance and replaced all of them within a couple years of buying the trailer new. You might see if you can tell if the trailer you're looking at had the grey/black tanks upgrade. They were originally supposed to be 50+gallon tanks (each). Carriage discovered that somewhere between design and manufacture they were closer to 45 gallons each. Carriage offered to upgrade the tanks to 62 gallon (each) tanks if the owner brought the trailer to the plant in Millersburg, IN. We took them up on it. Near as I can tell the only way to check this is to look under the trailer forward of the axles. IIRC the upgrade has about 6 inches of the tank protection/insulation protruding below the floor; non-upgrade won't. Maybe someone else on here can confirm that. I just don't remember for sure what it looked like before the upgrade. Hope this helps.