Not impressed with build quality of my MB
 

I have 2015 GL450. Bought it used with 14k miles on it. Love the way it drives and rides but not impressed with the build quality. So far it has not managed to stay out of the shop for one whole maintenance window. So far following has been fixed
Broken Latch on the center arm rest
Backup camera blackout
Rough shift from park to 1st and park to reverse
Tires gone and replaced at 25k miles
Both front struts replaced due to suspension knock
And today I discovered that there is water coming inside through the lift gate. Looks like coming from top center of the lift gate where the third brake light is. I understand mechanical and electronic things brake but this is ridiculous

25k miles out of a set of tires on these trucks is actually really good. Usually they don't make it past 15k. But you don't have 21" wheels and your V6 equipped truck is lighter than the V8 550's & 450's, so that is likely helping. The leaking you have is likely from a clogged drain channel or torn/cracked rubber seal. Since your truck is under warranty, I really don't know why it's such a big deal. I'm sure they give you a decent loaner vehicle when you take it in for service.

It is a big deal because I'm concerned about the longevity of this car. Planning to dump it before my extended warranty runs out. This vehicle should be able to go more than 3 or 4 k miles before something breaks.

How long is your "extended" warranty?

October 2020 or 100k miles

Smart you have the warranty. I wouldn't own a vehicle with the electrical/mechanical systems used on today's high-end platforms without one. If you can't afford the extended warranty, you shouldn't be driving the car.

My "work-beater" is a complete joy to drive. 43k mile hand-me-down 13' GL450. Maybe you just had a string of bad-luck and the next 2 years will be without issue? Good luck.