icing on the cake
n. an extra enhancement.Oh, wow! A tank full of gas in my new car. That's icing on the cake!Your coming home for a few days was the icing on the cake.
jazzed (up)
mod. enhanced; with something added; having been made more enticing.The third act was jazzed up with a little skin.It was jazzed enough to have the police chief around asking questions.
on the side
mod. extra, such as with a job or a side order of food.I would like an order of eggs with toast on the side, please.She is a bank teller and works as a waitress on the side.
spare tire
n. an unneeded person; an unproductive person.Gary is a spare tire. Send him home.You spare tires over there! Get to work.
to boot
mod. in addition.For graduation, I got a new suit and a coat to boot.She got an F on her term paper and flunked the final to boot.