Center headrest removal - Approach from behind; the left post has the traditional button, the right one has a small slot. You need to stick a small straight blade in the slot and pull up on the headrest to remove, usually working the right post, then the left upward. The first time you do it, the headrest is in there pretty tight, and might have you cursing a bit.

 

I race road and mtn bikes and have never had a rock or pebble or any debris hit my bikes. Seems like a lot of hassle to take the entire back seat out, andtake off your saddle and seat post. I have had a Thule rack on my A3 for almost 2 and half years with not one problem. I generally carry both my kids as well as an occasional fellow cyclist. I carry my bike to work at least 3 days a week for most of the year with zero problems. Good luck!

Cheers