Does having collisions in a particular race make any difference to the performance of the car in that same race?

I ask because sometimes in a Cup race I might speed my way quickly to the front, other drivers may not have the good sense to steer out my way, especially in the rather crowded Melbourne circuit. It would help I suppose if horns were provided! 

I can't notice any performance drop after impacts from other vehicles, but maybe others can.

In Le Mans at night I may wish to dip my headlights to offer a respite from the glare to myself and other drivers, but as there is no headlight dip switch yet provided, I simply lightly tap my front headlights once or twice with the rear bumper of another racer.

The auto engineer keeps offering to help out, but he isn't much use as expects me to win every race.

While your damage will reduce the condition of the car after the race, and may even cause your service mechanic to see red, it doesn't seem to effect the car in the race itself, or does it?