Solar Panels Loose?

Hello all, thanks in advance for any help! I have a 2010 Prius, solar panels, sun roof, JBL, the works. (I bought it used.)

Whenever I go over a speed bump at an angle, or over rough terrain, there's a big clunk form somewhere above and behind me. But I could never tell exactly where its coming from. t First I thought it might be something loose in the sun roof, but I don't think so. I made my wife sit in the backseat while I drove over nearby speed bumps, and she kept pointing toward the area of the roof that houses the solar panels. Can they come loose? Or can the roof struts come loose?

Anyway that leads to -- my mechanic is trying to figure out how much it would cost to get in there and take a look. He seemed to think that removing the headliner means buying a new headliner (i.e. removing it wrecks it.) That gets very expensive.

Anybody have any advice? The clunk is very annoying, sounds like the car is coming apart. Maybe it is!

 

78,000, and yes I got a carfax -- no accidents. Thank you!

 

Thanks everyone for the advice on this thorny, and still mysterious issue. One side note: I bought this car used in Feb 2016, and I didn't do enough due diligence. (Although I took it to a Toyota dealer for an inspection before purchasing.) Turns out the previous owner had had this problem and took it to the dealer, but then declined to do anything about it. I discovered this when looking more closely through the repair history the Toyota dealer gave me. Harumph.

Anyway since my post I was in a fender-bender and had to go to a nearby body shop. They did great work, and even offered to take off the headliner for a very reasonable price and check out the unfathomable clunk. They took off the headliner, drove it around, heard the noise, but could not detect its cause. They then let me drive around with them, headliner off, and I could not determine the cause! It's a mystery! So now I just drive the car around with the clunking noise over bumps, learning to live with it. Oh well. It's become my workhorse car for my new job, driving 30,000 miles per year. So I'll deal. Thanks everyone!