When they are that close you shouldn't be seeing them in the side mirrors.
IME, the side mirrors don't allow anything to be seen when they're that close. Instead, the side mirrors turn into rounded rectangles of pure glare. Only raised trucks and SUVs, driving way too close to stop if I needed to quickly and heavily put on the brakes, ever seem to be a problem, though.
I have to go with Nissan drivers as the worst, like a few others. They seem to comprise the majority of:
1. Double parking (not unsafe, but makes me want to be a vandal)
2. 2-footed driving (brake lights are randomly on, so not a useful indicator of needing to slow down or not, plus the obvious WTF of it)
3. Riding the brakes (if they only use 1 foot)
4. 'Getting stuck' while changing lanes, or entering traffic, near a light, instead of changing lanes in advance of needing to be in the far left or far right; or if entering traffic, waiting for a decent opportunity; and thus blocking multiple lanes of traffic, sometimes including from the oncoming lanes. For the most part, it seems those people are either really old, or driving a small to medium Nissan.