I believe you are asking whether one violates the issur of yichud when being in a car together with a woman. Rav Moshe here http://hebrewbooks.org/pdfpager.aspx?req=921&st=&pgnum=125 says it’s assur, except b’shas hadechak.
rav shlomo zalman says one can be meikil if the car has trasnparent windows. A key question you need to answer is if the woman can get a ride from someone else. If she can, mah tov umah noim. If she can’t, then perhaps it is a shaas hadechak and even rav moshe would say it’s mutar to give her a ride. in any case, consult a posek please!!