It's quite easy and I think most manufacturers of electronic devices, electric appliances and even cars are doing it.
You just have to calculate what the average working time during the warranty period and adjust the quality of materials and the build quality so the MTBF is just a bit higher than that time.
Cars are not doing it. Like I said: provide a source that isn't your own suspicions and anecdata.
I am a shareholder of an auto insurance company, and our actuaries would know if cars were doing it. There is a lot of very high-quality data about vehicle reliability, and major trends are very visible.
Car companies are often stupid and/or evil, but they can't (and don't) precisely plan obsolescence. Car usage is a huge bell curve, with the average American driving ~15k miles/year, but large groups of people driving far less or far more. You couldn't possibly plan a car to fail at X years.