In a word---no. The cowl vent is a structural part of the body shell. Some cars--like the 740/940 series have a removable panel at the base of the windshield but on the 240 it is a welded in part. That plenum leads to the heater matrix air entry at the base of the heater unit facing the firewall. With the entire heater removed (big job)that opening is accessible for cleaning out leaves, etc. The air coming through the winshield vent also gets directed to each side--providing air to the sidewall vent (easily removed) on the driver's side (pre-airbag 240 cars--and passenger side on 140/160 and non-FI 240 cars) and then into the rocker boxes (important that the drains in the rockers are kept clear). On the passenger side of FI 240's a closing panel and the fuel injection computer are mounted over the hole to access the inner fender area. The rocker boxes are accessible through plastic cap covered holes along the inner rocker panel (from inside the car). Leaves and dirt accumulate there. -- Dave