Will riding in a car with someone who is smoking cocaine have any effect on me?

Yes..

Yes, of course, it also gets on your clothing, and you breath it, While this can differ on location, also remember, in some places, if the police pull you over. And your friend has it, they can arrest everyone in car with the possession.

In all practicality, it is wrong to accompany somebody using cocaine. Rightly said by somebody above that police might pull both of you. Besides it would also have an effect travelling inside a car.

The second hand smoke will effect you, but the smoker will absorb most of the drug, it's the crashing and dying bit that will have more of an effect on you.

Make better choices!

Putting aside the legal ramifications and risk of being in a car where any substance is being actively used, it is possible to get a contact high from cocaine, but to what degree, and for how long is debatable, and depends on an individual's tolerances.

It's not a good idea to be in a situation that the effects are so unknown, and the risk is HIGH for BAD outcomes.

As well as what has been said above... if people around you are using drugs of any type... its time to change the people you associate with. They WILL hold you back in life. And keep you from reaching your potential to get ahead.

It is highly unlikely you would test positive (on any type of test) for cocaine. On the other hand if you did inhale some of the second hand smoke you might get a little bit of a buzz. You might want to be carefully about that.