An assembly includes a dash and a deployable panel supported by the dash. The deployable panel is moveable relative to the dash from an undeployed position to a deployed position. The deployable panel has a proximal end at the dash in the deployed position and a distal end spaced above the dash in the deployed position. An airbag is supported by the dash and is inflatable to an inflated position. The airbag abuts the deployable panel when the deployable panel is in the deployed position and the airbag is in the inflated position. A tether extends from the airbag to the deployable panel in the undeployed position.