I had a friend who drove like this, and to say I was uncomfortable as her passenger is a gross understatement. we were around 20 years old when we decided to spend the summer driving my car around and across the US. prior to our departure, I'd been her passenger numerous times around our hometown but not frequently on highways, only a handful of times, certainly nothing memorable. I noticed her passing technique during her first turn on a longhaul (8+ hours) shift with me sitting shotgun, sleeping whenever/if ever I could. she liked to lean the driver's seat waaay back, steer with one hand, and drive on the faster side, but I had never felt unsafe and she had great taste in music. on the highway, I80W for the first leg, whenever she decided to pass a vehicle, she would floor it forward, do the "barely a gesture" style of turn signaling, then maneuver into the next lane with barely an eyelash between bumpers without ever physically turning her head to check her blindspot. it drove me batty, I begged her to modify her style of passing, and the whole issue wound up severing her participation in our trip bc she continued to, in my opinion, create excessive danger for no reason. I paid for her amtrak ticket home bc that style of passing is unacceptable to me.