A practical evaluation
of a vehicle
When you want to take a car for a test drive, the dealer or used car salesman will probably ask for your driver's license and other paperwork; this is not only so that they have access to all your personal data (moohahaha!) but also for liability and theft purposes.
You will probably be given a route; if it leaves out an important kind of driving (highway, mountain, etc.), insist on driving in realistic conditions. The route has almost certainly been picked to avoid revealing problems like a three-mile turning radius, a problem with sudden braking, a shimmy at high speeds, etc.
Ask the salesdroid politely but firmly not to engage you in conversation. It's not only manipulative, it's also dangerous. Keep your eyes on the road and listen carefully for any signs of weird noises. A sudden fit of coughing from the salesdroid most certainly counts as a weird noise.
Most importantly: test drive several cars in the same day, to get a feel for how tight the steering is, how well the cars accelerate, and how much comfort they offer. Then, later on, ask to sit in the car for a full hour. Listen to the radio, make cell phone calls, eat breakfast, put on makeup, do whatever you usually do. At the end of the hour, notice whether you're still comfortable sitting in that car.
A few hours spent on a thorough test drive (and test sit) will save you many days of hassle later on.