The thing is though, killing women does not make you a coward, it's an obsession or a purpose for them. Killing women doesn't make you weak, 90% of Jason's victims are women and he kills them through the act of sex most of the time. Granted he kills men, Jason's majority of kills come from women.
Also, the using the car actually does strike me as a cowardly act, it's actually quite a brilliant one. Just as the ads say, Stuntman Mike is a serial killer, the only difference is he uses a car instead of say a chainsaw or a machete. It's his weapon of choice and the smart thing about what he does is using the car.
Accidents happen all the time, he has a guranteed get out of jail free car with this method of killing. Plus, he wasn't drinking any booze that night and the girls he were following did drink booze and probably drugs (I can't remember if they did). I don't buy the whole "upper hand" belief for Stuntman Mike's motives.
Because in truth, there was never a motive established. Mike's reason for killing women is never stated and being a psychopath, it's impossible to tell why. I could easily speculate he kills them because he's been scorned by women, or thinks they have ego problems, it's too speculative.
I also don't think he's hiding behind his car, every killer kills people in different ways and does different things with his/her victims once there done. The really funny thing about Stuntman Mike that struck me was that he didn't seem completely 100% obsessed with killing the second set of girls.
After their little game (prior to being shot) Mike seemed happy with the fun he had and was planning on leaving, he didn't swerve back and try and ram them, even when they chased him, I think he was really done with them. His desire to kill wasn't anywhere near as heavily implied as was the first time.
I also think the ending kind of left two very odd questions behind. 1: what are they gonna do with the Vanishing point car now, give it back to the guy they stole it from all banged up? and 2:
Spoiler Below the fact they beat Stuntman Mike to death is NOT going to go over too well with the cops.
Even though we know he tried to kill them, they still killed someone who was unable to defend himself.
I know this is just end of the movie afterwards jibber jabber but it is something I am curious about.