Ive had one for a year and a half or so. Its a 2014. Bought with 64000 on it, I have 82000 now. Other than a NoX sensor, which you can replace at home for cheap, and a DEF heater, which is covered under a special warranty policy, I havent had any major issues with the engine. The timing belt has to be replaced at 100,000 miles, so thats coming up. I think a DIYer can do it.
I did find that you MUST use anti-gel fuel treatment on every fill up in cold temps, though. When that fuel filter freezes up, it wont start til you can get the car into a warm garage for a while. I wish this car had a block heater. For some dumb reason GM didnt automatically include one on the diesels. Stupid.
Agreed on the oil filter. Absolutely the most dumb location for a filter I have ever seen. Same for the fuel filter....its under the car, and you have to remove this large cover to get to it. So doing your own oil change and fuel filter change is very difficult unless you have a lift in your garage. Just stupid on GMs part.
Fuel mileage is ok. I average around 35mpg overall. I see 40s on the highway. But I do have a heavy right foot, always have. I could do better but choose not to. I have also found that tire selection is very important to fuel mileage. But Id rather have wider tires than the pizza cutter 215s that are standard.
When doing research, I found the transmissions can be an issue with these cars, esp the earlier models like I own. My trans had been replaced before i bought the car. You know that annoying stop/start crap on GM gassers now? The fuel saver on these diesels works by the computer putting the car in neutral when stopped at a light, then engaging the trans when you give it throttle again. Stupid idea. You get around it by letting off the brake slightly. So there's that.
I put a Trifecta tune in my car, about 50hp. All emissions intact. It woke the car up. Also, there was trans tuning included, and that cleaned up a lot of the "hunting" I noticed and smoothed out the shift points.
DEF sucks. Ive had to refill it once. Damn tank is in the trunk, so you dont have a spare tire. If you want one, buy a Buick Verano spare and jack kit. You can "remove" parts if you want, but I havent got to that point yet.
I did have an issue with the rear brakes eating up the rotor, but I think that was my fault for not doing my normal brake maintenance last spring. Parts are cheap.
I added the factory nav unit to mine. I found a place here in Michigan who can reprogram the silver boxes to clear the VIN and work with the options of the car.
Build quality is good. Interior is roomy for 2 people. Kids would be comfortable in the back seat, adults get cramped. The car is not loud on the highway, and engine noise is kept to a minimum thru use of more sound deadening (from the Verano).
If you sit farther back in the drivers seat and like having the window down, you'll get buffeted by wind really bad. If you sit up closer to the steering wheel, its not nearly as bad.
Overall, its a good car. Would I buy one again? Probably not. Too many stupid engineering decisions made by GM that hurt overall ease of use and performance. DIY maintenance is an issue. The fuel mileage is not that much better than a 1.4 turbo Cruze, and diesel fuel just wont come down in price. So consider that.