Tomy Jumpsters "KITT"
This is a small (7,8 x 3,9 x 4 cm) black plastic Pontiac Firebird look-a-like car that jumps (read turboboosts). Ok, in the 80's it surely was called KITT for us kids who moaned for our parents to buy it for us. You arm the car by pressing the button in the middle of the car. Then you send the car in forward motion and in random (as far as i tried it) distance the car will jump upwards with some string mechanism.
This was a very common toy in Finland among boys of my generation. There were some other "Jumpster"-models as well, but they weren't so heavily related to Knight Rider, if at all...
My car is constructed of two different cars I found from a junk collectors' fair. The plastic body and chassis as well as the tires tend to get some damage when used heavily in crime fighting

The writing on the bottom of the car says: "JUMPSTERS TM, (C) TOMY JAPAN, PATENT PENDING"
Here's the pic:
