In 2006 Subaru officially changed the name of the Impreza WRX model to Impreza STI. Thus, a Subaru dealership would be expected to contain a large number of model STI autos. Given that public health officials have also recently introduced the term STI to accompany the more well known "sexually transmitted disease," or STD, the pun is a relatively young neologism.
B-"Gary is a friggin Subaru Dealership."
A-"Britnay Terple has had more sexual partners than there are chemical elements."
B-"Terple Subaru is open for business."