Need for Speed 2

Hold down [Shift] while entering one of these:
* Cheat codes:
PIONEER - Gives the cars huge engines
SLIP - Enable Super Slip & Slide Mode
tombstone - bonus car
bomber - one more bonus car
fzr2000 - bonus car genius (like Me BBTBG)
pioneer - pioneer mode
hollywood - secret track

They will give a message telling what happened.

* Vehicle codes:
ARMYTRUCK -- Gives you an army truck
BUS -- Gives you a school bus
BMW -- Gives you the BMW
JEEPYJ -- Gives you a Jeep YJ
LANDCRUISER -- Gives you a Landcruiser
MERCEDES -- Gives you the Mercedes
MIATA -- Gives you a Miata
QUATTRO -- Gives you the Audi
SEMI -- Gives you a Semi truck tractor
SNOWTRUCK -- Gives you a Mercedes Unimog
VANAGON -- Gives you a VW Vanagon
VOLVO -- Gives you the Volvo wagon
VWBUG -- Gives you Beetle
VWFB -- Gives you the VW Fastback

* Secret Routes
Pacific:
Just after the long winding segment past the start/finish line, there is a parking lot to the left.
Pull a quick left turn, go through the lot and the grass beyond, and swing left back onto the track.
If maneuvered correctly, this can shave about two seconds off your time.

During the long straightaway along the coast, there's a trail through the trees parallel to the road.
Driving on it is no problem and may actually improve time, but you've gotta get back on the road because the trail ends at a big rock.

Mediterranean:
Drive around the left side of the first big windmill.
Here's another chance to travel alongside the road, although this time it'll only slow you down.

The guardrail is broken on the right side of the road just past the columns (after the tunnel).
You can drive off the cliff and cruise around on the beach for a few seconds.

Another broken rail is located where you are driving alongside the cliff under the big wooden supports.
The fourth support is broken and driving over the rail past it will send your car sailing off into space
(Information from Cheat Machine)