We tend to think about humans and problems rationally, and, in doing so, we assume rational actors. (We know better, but this is more of an initial tendency, and as humans, we do other irrational things, like cling defensively to our first thoughts.) Buying a car is, at surface-level only, a rational decision. How much can I afford without impacting my other goals? What features are required? What will be nice to have? Some of us even succeed in answering these questions, negotiating with cold indifference, and getting a great deal on an apparently near-perfectly suited car for our needs. Many of us... do not.
As you're visiting your parents, eating a meal, you mention that you're car shopping. Your dad rants for a few minutes about how dangerous the interstate has become, and how he'll never drive anything smaller than his truck. Part of your brain remembers that time you were on the highway, and a tractor trailer started coming into your lane. You remember how the snow plow covered your windshield in slush. You feel fear. Your sister boasts about how comfortable her Lexus is. Again. Your mom says "that's such a nice car!" You feel envy.
You research cars. You find several suitably fitting vehicles. You talk to your bank and you determine a limit on what you're going to spend. Does everything go as planned? You visit a dealership. You talk to the dealer about the exact car you want. You take it for a test drive. For some reason, it's a clunker. There's a weird light on the dashboard, and it keeps making a buzzing sound. It just doesn't feel right. You know you should thank the dealer and be on your way to the next car you see, but you decide it can't hurt to drive some other cars just for comparison. While the sub-compact hatchback was a good idea, there's a brand new sub-compact SUV that's only a little more expensive, but roomier, boasts AWD, and you know you'd be one of the first of your friends to have this model. (Your rational brain says this is a stupid thing that you shouldn't listen to, but the voice in your head is drowned out as the salesperson points to the new smartphone connectivity feature in the radio. You don't care, and you largely ignore them. You pull out onto the road.
You feel optimistic about this car. Why weren't you looking into these? This has nice visibility. It seems to move easily and smoothly down the road. Your butt feels good in that warm seat. But that's stupid! You're not going to buy this. You're just taking it out for comparison. You complete your drive and hand the keys back to the salesman. They don't even have to say anything. You ask some more questions about it anyway. You feel excited. They invite you in to talk, just talk, while they check out your trade-in. You crunch some numbers on your calculator app. You double check the pre-approved loan amount. Hours go by, and you don't know why you're still sitting there talking about buying this car. You're hungry and you're ready for this to end. You agree to some things and sign some papers. They hand you a pair of keys...
The automobile manufacturers know all this. They've always known. They can build a Chevrolet Sonic, a Chevrolet Trax and a Buick Encore all based off the same platform and major components. But when it hits the dealer lots, they'll sell for $17k, $23k and $29k respectively. The cost of upgraded trim is almost an afterthought at the factory. When you make your 60 monthly payments, it's $50-100. No big deal. You feel like you made a great choice. You even got that one hint of jealousy when you showed your sister how you could pair your phone up to your new car and use Apple CarPlay. Her slightly used Lexus doesn't have that yet. Your lizard brain won this battle. It often does.