Vibrations in the rear of the car?

[Exhaust]

Hello everyone so I am trying to figure out these vibrations that are being translated to the rear of my car. I used to always mount my gopro on the rear window with the suction mount but noticed it kept falling off recently. After I recorded a video tonight I see what the issue is, there is a **** load of vibration on my rear window now and im not sure why.

I recently took my car in for an oil change and they did tell me I needed an alignment but its minor and is not needed immediately. I plan to get it done when my trip finishes but the vibration has me feeling a little off. Any ideas? Tire pressure is good on the rears.

Edit: To add, I dont notice any vibration in the car while I'm driving, no notice of handling difference however watching the video it seems it only happens at high speeds (60+).