Heliotropism isn't the plant growing towards the Sun (which direction is towards the Sun?); it is the plant turning its leaves towards the Sun.
Even if the plant isn't growing, they will still display heliotropism; facing East in the morning and West in the evening.
As far as a vine growing over a car, that is what vines do. They grow over things and “rob” them of their sunlight; luckily for the car it doesn't need sunlight.
So, if I am driving down the street, and I turn the steering wheel, which turns the front tires in that direction, you are telling me that I won't actually turn left, but my tires will be facing it as I go by?
I apparently didn't communicate well. The vines grew straight towards the car bumper, from 40 feet away, and wrapped themselves around the bumper. They followed the top of the ground, until they got a few feet away, then started growing at an approaching angle, until they get exactly to the bumper. They did not go any further. They simply spiraled themselves around that bumper.