Technically all it does is just force the small air buildup in your joints out. Though my professor yells at people who do it and tells them it's not good...he has a Ph.D and I have a huge amount of respect for the kind of knowledge he has so...I don't know.
You better not be one of those people that never uses turn signals. Way too many people don't realize how bad manner it is to not use them.
It's also really bad manner to be in the left lane and going slow. It's an unspoken rule, but you only use the left lane for passing (going faster than) the right lane. If you ain't passing, get out of the left lane.
Fun Fact: If Stork[gm] hadn't blown every single finals he's been to in tournaments, he would easily be the greatest player surpassing even NaDa. Sadly he will be know as the progamer that has 6 silvers and 1 gold.