A gesture made with the hand by placing the tips of the thumb and index finger together. Like forming the "okay" sign but shown from the backside and below the shoulder. The idea is to get another person to glance at it, earning the right to punch them in the arm. The poonstance can be negated however by the viewer putting his finger through the ring that is made by the thumb and index finger. From a game often played by young adult males.
A Ford Mustang (and "poonstang",)because most of them are driven either by: cocky teens who didnt pay for them, girls that have them...but only the POON V6 version, or by some older man that is too scared to actually race it. ALTHOUGH I respect the people that actually buy a classic, or a new cobra or saleen, and actually build it, and race it.. But to all the slow fags out there...like in 909..."Dsm Boost Ownz J00!!!!!