Rubber surfaces create friction and static that efficiently gathers loose pet hair from fabric.

Rubber Glove Method: Put on a standard rubber household cleaning glove. Lightly dampen the glove with water (optional, but often helps). Wipe your gloved hand firmly across the car seats and carpet in one direction. The pet hair will ball up and stick to the glove. Periodically clean the hair off the glove and continue.
Squeegee Method: Use a rubber window squeegee (the kind used for cleaning windows). Drag the rubber edge firmly across the upholstery or carpet. The hair will accumulate along the squeegee's edge, forming clumps that are easy to pick up or vacuum.
Follow up with a vacuum cleaner to remove any remaining loose hair.

N/A - Simple, highly effective, and inexpensive methods using common household items to physically gather stubborn pet hair.

Use Damp Rubber Glove or Squeegee