Excessive dash/front movement

[Jeeper44]

I purchased my 2001 Diplomat at the beginning of this year. Due to other circumstances I haven't driven it very much, with the three hour trip home from the dealership being the longest. I noticed while driving there seems to be a lot of movement between the dash and the front of the coach. I don't know if the dash is moving, or the front is moving. I've read about people having windshields pop-out due to the amount of movement in the front. Should I be concerned, or is there anything I can check for loose brackets, perhaps that hold the dash in place? I found two of the supports for the generator door weren't even attached to the frame, so I fixed that.

[BradHend]

I have a very new to me ‘05 Monaco Cayman that does exactly that as well. I Mentioned it to the seller while test driving and he just kinda shrugged his shoulders and said “ya, it’s an old coach, and it flexes”. He didn’t seem too concerned about it.  I’d be interested to know if others experience that or not as well.  
Mine is fine on normal roadways, but negotiating larger uneven turns and what not it makes me want to remove that piece of trim that covers the windshield frame to dash.  sounds terrible.