Yep, the ts overlay isn't fixed to anything. In the original housing, it's clamped between the front bezel and the lcd-panel, just like in your dash I guess...
Ive fabed my screen into my dash using the front panel of the xenarc. When i took it apart the touchscreen wasnt ad all stuck to the LCD itself sealing it from dust etc. So i did the same and put it back in the dash like it was, just in affect resting onto the LCD. Is this unusual? Im thinking about taking it apart and sticking it usign the double sided strips that are on the touchscreen but not even used as its letting in dust and also if i push up and down hard enough it moves the touchscreen up downa a few mil. have you guys found the same?