[dsraven]

I recommend to sit in the cab area and place your feet where the pedals would be. Nothing worse than a cramped accel pedal on a long ride and you need room for your foot to access the brake pedal easily. Try to make the firewall recess as narrow as possible. Maybe even a removable cover like a van has. Also think of shape if you plan on upholstering it. If a wheelbarrow is the shape you like but too wide, you could split it and seam down the middle. If going with sheet metal from scratch, mock it up with posterboard or even wood veneer and tape.