Hi all, it's been a long, long, long time since I've had the old Bee apart and I forgot what side the rear defogger unit goes on ...driver or passenger.

Later, BUZZ

from my really AWFUL memory, if you look under the package tray, there will be an opening for the speaker that will fit it [kind of] flush with the tray.
the other opening will fit the defrost unit with it's gasket attached.
i don't know if this helps or not. i tried looking in my 70 FSM under the Heating and AC chapter, the body and the interior groups, but i found nothing except the front under dash information.
i probably missed where it is, sorry.

The blower mounts on the left side with the outlet pointing to the center defost duct.

This, and then the wire runs over the top of left wheelhouse and down to the inner rocker then forward to switch.

after i made my comment, i looked closer at the FSM, and although i couldn't find mention about the rear defrost, i could clearly see the mounting surface for it on the package tray picture.
as said, it was clearly on the left side, with [of course] the vent outlet in the center.
even though this was a 1970, i took a peak at my charger, which is a 69, and it was [basically] the same. same [basic] cut out and mounting surface, and same [basic] vent shape and location.
this prompted me to do a little [snooping ?] investigating, and the A-bodies of my buddy's 71 duster and 73 dodge sport are somewhat the same in the package tray area. it looks like a defrost assembly could be mounted in the [somewhat] same location, and the vent used in the middle.
now with that said, is it possible defrost units were mounted to the left on all body styles that had this as an option ?
if so, how does this affect rear AC units installed on new yorkers and imperials ?
remember, i'm just throwing this out there, and although i have owned imperials with rear AC, [plus scrapped some in my junkyard ownership days] it's been so long ago, and i don't have any FSM's to refer to.

My 70 Challenger TA has the blower motor on the right and the speaker on the left.

Same on the AAR Cuda

E-Body is different that an older b-body

well that blows my wondering "if" all to pieces...........
any C-body location confirmations ?

Mine has an offset bracket in my 70 Charger. I have a 5 speaker system with an AM 8 track radio, with the 3 speaker dash and also two under the rear deck. The blower has a bracket that mounts off of the speaker.

Thanks.... to all that replied, so I climbed my lazy ass into the trunk and had a good look at this %*&@# ! defogger set-up and to my surprise, it mounts on the right (passenger) side. Also, it can only mount in that location cause the defogger mounting plate is an oval 6x9 shape and the matching 6x9 oval opening is on the passenger side, The hole on the driver side is more of a square design and smaller looks like maybe a 5x7 speaker would fit there. To sum up all has been installed, tested and working.....PLEASE note this is on (MY) car a 69 Superbee, might be in a different location on other models/ years. Again thanks for all the info and replies.

Later, BUZZ