One embodiment of the present invention relates to an adjustable bracket assembly for mounting to a vehicle. The bracket assembly comprises an integral planar attachment portion, at least one integral mounting portion separate from the planar attachment portion, at least one integral locking portion separate from the attachment portion and at least one integral keeper. The integral planar attachment portion includes a reception portion, wherein at least one of the planar attachment portion and reception portion include at least one slot. The at least one integral attachment mounting portion includes an engaging portion and a mating portion that engages the reception portion, wherein at least the engaging portion is substantially parallel to the planar attachment portion when engaged. The engaging portion includes a receiving portion having diameter “drc” and a radius portion in fluid communication with the receiving portion, the radius portion having diameter “drd”, wherein drc>drd. The at least one integral locking portion engages the attachment portion, and mates with at least the radius portion. The keeper has a diameter “dk”, wherein drd−dk=α. As α approaches a manufacture tolerance, drd approaches and is substantially equal to dk.