Coming up for auction at the RM Sotheby's Amelia Island sale in March, this stealthy 1990 Porsche RUF BTR Carrera 4 Turbo is bound to appeal to collectors who want a little something extra out of their classic Porsche and appreciate simplicity as much as iconic German design and a wonderous amount of horsepower. As always, we've got an early look for you before it hits the block.