My 2004 was built in Oct 2003. So it hit its 10th birthday this last fall. For all intents it will be "9" years old for the rest of it's life. I think in 40 years of camping I've only run into this question twice. In one case I remember they guy asking the question as he glanced out the office window, and in the same breath he said, "oh you have an Airstream. No need to ask you this question.". In the other case I had a Hi-Lo and while it was over 10 years old, when the guy asked the question and I honestly answered, he walked over to the door and looked at it and said you're okay. That trailer was always garaged and looked as good at year 14 as it did on day 1.
On the other hand the only case of campground thievery I have ever run into was at a large campground in Myrtle Beach N.C. Folks pull up next to my site in an absolute wreck of a trailer which was most likely in excess of 10 years of age. The thing truly was a mess. I remember that the folks had no bumper caps for their sewer line hose, and also no wheel blocks or stabilizers. The air conditioner shroud was partly missing also. I remember when setting up they had to go to the campground store to buy a sewer hose. It really looked like it was the first time they had the trailer out. It was leaning to one side due to it not being level and they used a towel for a door mat which became muddy since they covered a low wet spot in front of the door step with the towel. They bought a sewer line hose at the campground store.
The occupants were two young guys and a gal with 2 small kids running around all day in diapers only. Bottom line the following day one of the guys broke his leg while there (don't know how he did this). Next day they were packing up to leave. I was sitting in my car with Patty and wrote some last minute checks out. They were pretty much packed up and they were staring at us sitting in the car. Once done Patty and I went to the post office to mail some bills. We got back and I noticed they were gone. I also noticed that my bumper caps were missing from my SOB trailer and my aluminum aircraft wheel chocks (my brother who is a pilot gave them to me) were also gone. I'm pretty sure those folks took them and I'm surprised they didn't take my stabilizer jacks too, unless they felt that the trailer might have rolled away. Maybe a 10 year old rule might have saved me. Who knows.
'04 Classic 30' S.O.,'03 GMC Savana 2500,'14 Honda CTX 700