It was either taken off the market temporarily or was sold. You can search for all available vehicles here.
Model info:
The Dodge Viper is a sports car known for its high performance and distinctive styling. The Viper was first introduced in 1991 and has since gone through several redesigns, with production ending in 2017. The Viper is known for its powerful V10 engine and for being a driver-focused sports car, with a manual transmission and rear-wheel drive. Viper was discontinued in 2017 at which time the average MSRP was $142,700.