The AR15 is a Dodge Charger
By means of Googling “AR15 Upgrades” we yielded 461k results. Followed by searching for various commonly upgraded vehicles (Mustang netted 600k, Camaro 518k, Focus 661k) BUT the closest result is the Dodge Charger with 463k results.
So there you have it.
*Update - It appears the Dodge Charger is now banned in California and New York.