Dash Rattle in 2012 Prius Four

I live in Oklahoma City but purchased my Prius Four from Richardson Toyota in Texas. My son lives there and we drive down often and of course I realize I can have it serviced at any dealer I choose.

I picked it up late on a Saturday evening and on the way home noticed a very bad rattle in the dash. It was not only noticable on even the slightest rough road, but if I tapped the top of the dash with my fingers I could cause it.

Long story short, my wife stayed in Dallas and took it in the following Monday. They acknowledged the rattle and later that day called her and said it was ready. She came back to Oklahoma City and the next day I drove it to work. I immediately heard the rattle again, but only on certain rougher roads.

It's been two months and it hasn't worked itself out. I plan on driving to Dallas Tuesday for the holiday and I'm going to make an appointment for them to look at it since they have the record of what they did (or didn't do) originally.

My question (finally!) is whether it is worth having the top of the dash removed or if it will more than likely cause even more rattles. My other car is a Lexus LS 460 so I'm spoiled in terms of build and lack of creaks and rattles. What should I expect of a Toyota dealer on a noticeable and demonstrable rattle? Will they even bother or should I start looking at PDF's on taking the dash apart?

Thanks in advance!

 

Actually it does seem to be emanating from there. I can tap the dash pretty much anywhere and make it rattle, but that's where it is coming from. Perhpas that service bulleting wasn't out when I picked up the car. thanks!