An Oldsmobile of that time period would have had an inside hood release.Maybe the neighbors thought they were home all day because they saw a car parked there all day--the Olds 95. In those days you could pop the hood on a car from outside the vehicle. The cops should have popped the hood on the Olds to see whether the engine was still warm. Maybe the Olds was moved into position right before Fran showed up at the mall.
However, the hood would probably have been warm if the car was driven recently.