Totalling your car is when you do so much damage to your car that you cannot race with it anymore.
 Need for Speed: Underground
In Need for Speed: Underground you total by crashing into other cars whilst drag racing.
 Need for Speed: Underground 2
On Need for Speed: Underground 2 the only way to total your car is in drag if you crash or blow your engine.
 Need for Speed: Most Wanted
In Need for Speed: Most Wanted you total car by crashing into anything during a drag race.
 Need for Speed: Carbon
 Need for Speed: ProStreet
In Need for Speed: ProStreet, you can now total your car at any time if you crash and other cars you are competing against can be totaled. In a drag race you can blow your engine, crash and total or have an early start.
Related ThreadsWhat is your total bounty? - last post @ May 20, 2009
What is Trade in total - last post by @ Mar 11, 2006
total junker look / rust bucket look - last post by @ Jan 3, 2009
totally stuck - last post by @ Aug 24, 2005
Total spend on car? - last post by @ Apr 28, 2006