A smaller scale version of the 2016 Ecto-1 can be found in the LEGO Dimensions set 71242-1.
For versions of Ecto-1 based on the 1984 film, see set 21108-1 for a large scale LEGO Ideas version and set 71228-1 for a smaller scale LEGO Dimensions version.
N.B.: The torso and head designs for the Jillian Holtzmann minifig are correctly included in the inventory. However, the set image displayed is based on official LEGO artwork used on the packaging and incorrectly uses other torsos and heads from the set.