Q: Why is it taking so long to wrap up this car purchase?

A: Usually one of two things is going on — or maybe both: You're shopping on a weekend or you may not have all the documents and information you need to do a car purchase.

Foot traffic at car dealerships is lowest on Tuesdays and peaks on the weekends, when most people have their days off. While there may be plenty of salespeople on the floor, the bottleneck typically occurs at the finance and insurance office (also known as F&I — we'll talk more about that later).

In the finance office, a manager will likely offer an extended warranty or other products and, of course, this is where you'll sign the sales documents. Fewer people work there and each customer might be talking to one of the finance managers for 30 minutes or so. While all this is going on, your new car is being washed, gassed and prepped for final delivery. If that process doesn't sync up exactly, you might have to wait a while longer for the car to be ready.

The other thing that takes time is, obviously, the deal itself. The average car sale takes about four hours. Yes, it's a long time, and that's because there are a lot of pieces to it. The dealership needs to run your credit, get your loan approved, appraise the car you're trading in, figure out the pay-off amount to your current car and agree on a price for the new car you want to buy.