So I work on cars on the side to help people out. I've also owned a few that had issues straight from the manufacturer that many people don't find out about until they experience the issues.

List some that you've dealt with that left you mind boggled or pissed that the manufacturer would even build such a pos.

The Mercury Monterey...a minivan that was relatively well built except for the torque convertor. Apparently the torque converter's interior gear would fail causing the vehicle just to stop moving. After thousands of failures Ford/Mercury (Ford Freestar was Fords version and had the same problem) eventually did a recall and paid for the torque converter replacement. However many converters failed again.

2009 Nissan Altima...I'm not a big fan of Nissan especially from this time frame. So the Altimas key fob would quit working. You'd drive to the grocery store or out to eat whatever, you get back in your car and the car won't start. Car no longer reads the key fob. You have the car towed to Nissan and they charge you 1000 (actual quote) dollars to fix an issue that was because of a faulty part they installed on the car.
After leaving thousands of people stranded Nissan eventually recalls Altimas from this year range and replaces part with a nondefective part. Actual cost..147.00

Ford 500...those that are luckily enough to own this gem have a few built in defective parts and a engineering design flaw. One of which is the wire harness that comes from the firewall to the engine is draped over and on the metal ac lines. So after a few 1000 miles the metal rubs through the harness and shorts out everything. Lucky you. Another issue is that the pcm controls the voltage regulation from the alternator. Due to a design/program flaw the pcm will have the alternator send 18+ amps to the battery which over time fries the battery. And for good measure the throttle body also has a defective part, throttle position sensor, that also likes to fail. You get to replace the whole tb just for kicks and giggles.

2017 generation Ford F150...I generally like Ford F150s but the starters on this generation of F150 have a plastic part in the solenoid that breaks and doesn't always allow full retraction of the starter gear. What you get when this happens is one of the loudest noises you'll ever hear besides throwing rods. Of course because sometimes you get the retraction and sometimes you don't the noise comes and goes. Replace starter

Fords transmission problems - 6/10 speed. The 10 speed is notorious for the “adaptive transmission shift strategy” problem with multiple lawsuits ongoing. Multiple suggested fixes are tunes, resetting the transmission program, etc etc etc. Ford won't recall but has sent out service bulletins for the issue.
The 6 speed has less issues and is more of a shifting solenoid issue due to possible dirt in solenoids.

Ford cam phasers...the Ford F150s with the ecoboost have a manufacturer defective cam phaser. Basically it will sound like a lifter knocking from the top of your engine usually on the passenger side. Reasons for the issue is that Ford built this super cheap cam phaser and installed them on this vehicle. Replacement phasers are more durable. Also it's suggested because of the oil route throughout the engine that it hits the passenger side last causing nonlubrication and premature failure of the part. The knocking usually happens at startup and will stop after a few minutes. Must be replaced and will cost a good bit of time and money to do so.

Good ole Dodge Rams with 4.7 engine. 4.7 has a known defect in that the bearings will slip eventually leading to drops in the oil pressure. The dealer will try to have you replace the oil pressure sensor but it will be the bearing and you'll need a full bottom engine rebuild.

Let's not leave Chevrolet out...HHRs. Hhrs have a design flaw in the transmission where the solenoids are not in the bottom of the transmission but up high. Which causes a nonlubrication issue. They'll get hot, especially the very top one, and will melt the wires to the solenoid. Loss of solenoid will cause shifting issues and check engine activation.

Those are just a few I've experienced what are some that you guys have dealt with? Hopefully this will help someone with these issues.