Rack-and-pinion steering
Delivering a more precise feel than recirculating ball systems, rack-and-pinion steering is a common type of steering mechanism on modern automobiles. In simple terms, it consists of two gears that convert rotational movement into a linear one.

One of the gears meshes with a rack (a toothed metal bar), which in turn is directly linked to the wheels via tire rods. By rotating the gear with the steering shaft, the circular motion converts into a linear one and moving the rack from side to side, therefore turning the wheels into the desired direction.
Ramp Break-over Angle
The ramp break-over angle measures a vehicle's ability to safely pass over a ramp without touching its underside. For the best break-over angle possible, a high ground clearance together with a short wheelbase are necessary.
Rebound is the opposite of jounce, so it's still a vertical motion of the wheel. In other words, when the suspension springs back from a jounce, the term used to describe this motion is called "rebound".

Recovery Strap
Used mostly in extreme off-roading, the recovery strap uses kinetic energy (in the sense of a bungee cord) to help free a mud stuck vehicle by linking it to another vehicle which has traction.
Road sensing suspension
Road sensing suspensions use various sensors to gather input about the vehicle's body movement and control the dynamics of the suspension via a central ECU and either hydraulic or air installations. Most of these types of suspensions were developed in order to ensure ride smoothness and reduce the effects of disturbances on the surface of the road.
Rocker arm
The rocker ram is only found in pushrod engines. It is in essence a small reciprocating metal arm that pivots to open and close the intake or exhaust valves when the camshaft raises/lowers the pushrod.
Roll Stability Control
The Roll Stability Control (RSC) is a safety system introduced on vehicles manufactured by the Ford Motor Company (mostly SUVs) . Since its integrated in the Electronic Stability Control, when a potential rollover situation is identified by the onboard sensors, the RSC will automatically and individually brake each wheel or even reduce the engine power, thus improving directional stability, which in turn helps to avoid a rollover.