As written, the INA trait was intended to serve as a penalty for using large-scale weapons for direct attacks on characters. I think we can all agree that using an M1A1's 120mm Rheinmetall to snipe a mastermind, while gratifying, is baaaaaad. The disconnect here seems to be that vehicle' Size-inflicted Defense reductions don't scale at the same rate that INA penalties do.
Yeah... people should never use them like that. After all Stingers never played a real role in espionage movies... *Sarcasm Sign*Goldeneye
= car was equipped with stinger missilesThe world is not enough
= car was equipped with stinger missilesLiving Daylights
= car was equipped with stinger missiles and they were under synchronized shootingLicense to Kill
= car was equipped with stinger missiles... and hey it was actually part of the film's plot too!The Spy who loved me
= lol he actually shoots down a chopper from underwater with a missile coming out of his Lotus Esprit (I'd like to see the penalty on that!!)Diamonds are forever
= the Aston martin DBS can be seen in Q Branch being equipped with guess what? Missiles!Tomorrow never dies
= car was equipped with stinger missiles. okay in this one, a random mook displays the horrible miss that one can achieve with a rocket launcher.Die another day
= usual refinements, which include? Missiles
Considering the above, I'm pretty sure that the rules were made to hinder player abuse, but if you give a Stinger launcher to an intelligent Schemer or a Forward and add to the formula: Guided Weapons Basics. I can see things are gonna start to be nasty. It can get uglier, however.