on the dash

The other definition is false. On the dash does refer to the dashboard of a car, specifically the gauge panel. The number refers to the highest speed on the speedometer.

The Boss - Rick Ross
I've got a Chevy with a 454 in the hood and it's got 125 on the dash.
(Most classic muscle cars displayed a top speed of 125 on the speedometer.)

T.I. - Big Things Poppin'
Think I won’t pull up in something with 200 on the dash.
(High-end supercars, particularly of Italian origin, commonly have the top speed of 200 on the speedometer.)

on the dash by suburban white boy June 27, 2008

live the dash 

a shorter way to say live every day to its fullest; on your gravestone, it will show the year you were born and the year you die, in between is the dash. That is the time to live each day to its fullest.

Birgit is learning to skydive, she is going to live the dash.

live the dash by jmodog May 17, 2010

doing the dash

To go really fast.

" I was doing the dash in this car I just bought. "
" I seen him coming so I did the dash on him."

doing the dash by GodSpeed July 13, 2014

do the dash 

Going high speed in a car.

"Im bout to do the dash, the 5'0 behind us"

do the dash by Yungboyy17 October 7, 2017

on the dash

refers to the dashboard of a car; an associated number indicates the total amount paid for a vehicle including any modifications made (e.g. the price of the car, rims, stereo, engine upgrade, etc.)

think i wont pull up in somethin' with 200 on the dash....
i've got 125 on the dash...

both instances used so as to say, my car is worth, for example, $200,000 or $125,000 respectively

on the dash by b/real March 28, 2008

Max the dash 

Going as fast as possible in your ride

"Last night when I was driving drunk home from the rave I decided to max the dash in my outback Subaru."

Max the dash by Phifester February 20, 2009

Salted the Dash 

When a person attempts to have sexual intercourse with a jar of Mrs. Dash and ejaculates into it.

Phrase originates from Michael Ian Black's Twitter.

Yeah, I Salted the Dash. She was begging for it. That bitch wanted salt all over her . Then I licked it off her like a bull mastiff.

Salted the Dash by tombot5000 September 23, 2010