(triple-post, my apologies)
Been messing around designing what a dash and interior might look like for a one-seater. This one is designed to fit within a chassis frame that's 30" inner width. Can't really think of what else a person would need in there...
MP3 player dock (Blackberry?), two USB ports, master On/Off switch
MPGuino with buttons
Headlights On/Off
Dome Light On/Off
Hazard button
Oil Temp digital gauge
Fuel Level gauge
Voltmeter digital gauge
Speedometer/Odometer
Brights indicator
Gear indicator
Tachometer
Electric engine fan On/Off switch
Active Grill Block On/off switch
Exterior air temp digital gauge
Water temp digital gauge
Engine bay air temp digital gauge
Intake air temp digital gauge
Ignition key
4.3" touchscreen GPS, On/off switch
Rocker gear shift linked to motorcycle trans
Has 22" width seat with 3" wide armrests on each side. But no cupholder!