In 1970 Plymouth released the last production year of the first generation of its popular muscle car, the RoadRunner. The 70 RoadRunner brought many changes to the car, as well as a very neat promotional campaigns.
The 1970 Plymouth RoadRunner was still based on the original 1968 body as a platform but brought changes to the exterior design again similar to the 1969 model. The grille was updated, the front fenders as well as the quarter panels were replaced and Plymouth added scoops on the rear end of the car. These scoops were non-functional though. The already popular Air Grabber option, which was originally introduced in the 1969 model year, was further improved to increase the performance of the car. A nice additional effect was that the car looked even more intimidating. Plymouth added a switch in the dashboard that allowed the driver to slowly raise the scoops on the hood, which then showed teeth that were designed to remind people of a shark.
Plymouth did not add any new engines to the series, so the engines that were available for the 70 RoadRunner were the same three that were last introduced for the 1969 model year. Plymouth introduced a new transmission though: The standard transmission was changed to a heavy duty three speed manual one, placing the former standard four speed transmission on the options list along with the TorqueFlite automatic.
The 1970 RoadRunner was the last one where a convertible was available. The total number made was recorded as 834. Experts often times referred to the 1970 RoadRunner convertible as being the better convertible in comparison to the 1969 version, as Plymouth offered more options and better parts for the 1970 version.
The total number of sales for 1970 RoadRunner was 41,000. This is a 50 percent drop compared to the previous year, where Plymouth sold almost 82,000 units. This left Plymouth still in second placed, behind the Chevrolet Chevelle. The decline was not only felt by Plymouth, but every car company that produced muscle cars. This is largely due to several insurance companies introducing surcharges on policies for muscle cars. The change lead to very high insurance premiums for muscle cars. This increase in costs made the purchase of these high end vehicles a very undesirable one for many people. In addition to this, Plymouth probably cannibalized their own sales by introducing a lower cost but equal or even better performance muscle car called the Duster in 1970.