Hi Foxadams,   Your symptoms are consistent with that of a panic attack, however, I am a bit concerned when you say that you "grey out" for a few seconds.  Perhaps you are experiencing a feeling or "unreality" or you are dissociating for a few seconds, (both can occur during a panic attack) however, it is always best to have a physical to rule out any other medical condition.   You can read about the vicious cycle of panic to understand that anxiety begins with a trigger.  The trigger for you may be a combination of things, the physical sensation you have while driving at a high speed in the car, thoughts you have while in the car, etc.    You will want to start to rate your anxiety on a scale of 0-10, where a "0" is no anxiety at all and a "10" is a panic attack.  There are two reasons to do this: one so that you become more aware of what moves your anxiety up and down, and the other so that you can intervene when your anxiety reaches a "5" or a "6" so that you can prevent a panic attack from occurring.   It is unlikely that you can learn how to do this completely on your own, but you can get started!  Learn how to do abdominal breathing and progressive muscle relaxation (PMR).  Learn how to start to address your thoughts.   Most likely, you'll want to seek some help from a Cognitive Behavioral Therapist (CBT).  You can look for a therapist in your area by searching the Anxiety Disorders Association of America (ADAA) website.   Regards,   Jennifer L. Fee, Psy.D., Psychologist The Stress Masters