My wife knows that well... If not she wouldn't have dedicated herself to working giving blowjobs... it's wonderful to watch her suck and swallow strangers' semen...
When I get a blowjob in my car I always insist the cock sucker swallow. I don't need a mess on me or my car and especially if I'm driving my wife's car. When I suck cock in a car I always swallow.
You do know... I never sent her... But that's how my wife started... Not for money but for merchandise... I gave her a blowjob and she came with bags full... At 28 she decided to practice the trade!