great designer car, but

I’ve always been a fan of the Mini Cooper (yellow with black roof please). Now the Fiat 500 is a healthy competitor (though the interior design of the Cooper is clearly superior). Their size (and fuel economy) are appealing, but often I need the car to be larger. It’d be nice if the Cooper and 500 had switches that made the car extend to any size. Need kids car seats in the back? Bam, pull the switch three notches. Need to haul 12 foot lumber? Bam, pull the switch twelve notches. Just making a quick run to the mall? Bam, pull the switch back to default position.