A support for supporting an object such as audiovisual equipment within a motor vehicle in operable position for viewing by passengers of the motor vehicle. The support may comprise an expansible post comprising spring urged telescoping sections and an adjustable shelf. The shelf may comprise a collar having a setscrew enabling selective positioning of the shelf along the post both along the length and also at a selected angular orientation. A variable length arm may fix the shelf at a selected orientation within a range from vertical to horizontal when the post is vertically mounted within the motor vehicle. The post may have a soft pad for protecting the ceiling surface of the motor vehicle. The spring may be exposed at the bottom end of the post.