If your not bleeding, you aren't working... at leas thats what the SD tells me all the time.
my favorite scar caused by the car was when i was welding up the exhaust. i had the whole length of pipe out of the car, my friends mom called us to dinner, so i slung it under the car, the razor sharp edge of the pipe that i had just cut with a band saw sliced off the top of my pinky finger, not hurting the finger, just like it had been scalped, only the skin was missing. it healed up just fine after a month or so. you can only kinda see it, until i work on the car again. the grease and oil will get all over my hand, but will never stick to the scar tissue.
Its a bit of the Mercedes that will live with me always.