2015 Lexus RX 350 has a squeaking sound coming from inside the front passenger door

[ColoradoRX]

My 2015 Lexus RX 350 (80K miles) has a squeaking sound coming from inside the front passenger door while driving on a bumpy road or just by closing the door when parked.  I am ready to remove the door panel to further investigate, but I thought I would post this in case someone has encountered a similar problem.  Thanks for reading my post!

[RX400h]

I'm sure you checked the seatbelt, correct?

[ColoradoRX]

Thanks for the reply!  I don't think that the seat belt is involved with anything inside my front passenger door.  After removing the door panel, I am highly suspicious of the weatherstrip, front door glass, inner RH (Lexus 68171-0E020) slipping against the window glass and causing a "squeak.".  I currently believe my big decision is to 1) load some packing material against the weatherstrip's side wall to apply more pressure between the weatherstrip and the glass, 2) apply a reconditioner to the weatherstrip to improve its grip on the glass, or 3) replace the weatherstrip with a new one (gulp, $64). 

[RX400h]

Sometimes a mechanic's stethoscope comes in handy for pinpointing noises. I have one and it's come in handy at times.
But yes, dry rubber against glass could create noise from vibration.

[ColoradoRX]

Thanks, Dave, for your idea about using a mechanic's stethoscope.  I think I might get one to help me with the troubleshooting.