I'm planning on performing the bypass on my X920BT, but I have a question about it. The bypass instructions call for you to ground the yellow/black mute wire from the radio. Will this disable the auto-mute function of the unit when someone calls my phone? Will the radio still automatically mute when someone calls my phone if I have performed the bypass and grounded the yellow/black mute wire? Thanks for any help!

Will this disable the auto-mute function of the unit when someone calls my phone?

No.