Yeah I think you're better off pulling air from underneath and venting it out the top than letting it all go through the front... newer cars are made more like that.
However, I could see you having issues in hot weather with that warm air pulling into the cowl vents and cooking you.
I remember The RoadWarrior..To understand who he was, you have to go back to another time..the world was powered by the black fuel & the desert sprouted great cities..Gone now, swept away..two mighty warrior tribes went to war & touched off a blaze which engulfed them all. Without fuel, they were nothing..thundering machines sputtered & stopped..Only those mobile enough to scavenge, brutal enough to pillage would survive. The gangs took over the highways, ready to wage war for a tank of juice