You mean "Touché" (while we're being picky!)
Yes! And now you will know it forever. It's actually quite straightforward as soon as you know a few examples.
Cars you can count (one car, two cars, three cars, etc) so it has to be "fewer cars".
Traffic (for example) you can't count (one traffic, two traffics, three traffics doesn't work) so it's "less traffic".
I reckon "uni's" is perfectly acceptible. An apostrophe can mark an abbreviation, like 'phone and 'though. So uni' is right, and uni's is right too.
I'm trying to think whether I use 'uni's', I think I do but I think I use it as an apostrophe of possession.
personally it is know and no being confused that gets me. LOL strange how certain things grate on certain people.