If I may suggest an alternate approach: often new directors get caught up in how to make things
realistic. Especially in your situation, to get a realistic car to do the things that you might want, it could be excessively cost / labour /
etc prohibitive. So
switch gears. If you could only do it with lights, sound and the
props / set pieces you already have on
stage, how might you go about it? Use the imaginative
power of the audience. It's what makes live
theatre special. A semi-realistic car will usually feel like an incomplete car, whereas if I just put 4 chairs on a rolling
platform pushed by clearly visable actors accompanied by car sound effects, the audience will know exactly what I'm doing and won't be bogged down by the fact that it doesn't
look like a car. They know it's a car. I theatrically told them so.