To this statement, you may want to try to invest in some sound deadening in the rear, like Dynamat. I would suspect laying down a bunch over the rear arches and on the floor of the trunk may reduce some of this. Not for sure, but I think a good chance. Unless all the boominess comes from the big hatch itself.
I bought my Stinger originally with these two sentiments in mind (more of the first than the second though). Prior to the Stinger, I had a 2015 Mustang GT that I factory ordered. I learned I'm way too OCD for a car like the Mustang. Over the 3-1/2 years I owned it, I touched up paint chips and kept adding more and more stone guard to various areas that were getting hit by rocks. The interior was becoming an absolute rattle trap - the glovebox rattled, the dash over the cluster rattled, the b pillars rattled, the doors rattled. Everything rattled and ticked. Above all that, it was impossible to stop modding it, I just kept spending money on it. I decided in 2018 summer that I would just try to live with the rattles and somehow get over it, but then the rear end started to make a clack, I brought it to the dealer that really let me down, kept it for two days and figured nothing out (they didn't even touch it til the end of the second day even though it was scheduled in) and when they couldn't do anything, that was it. I had already test driven a Stinger prior and was reasonably satisfied with it, so off to Kia I went...
I test drove a blue Stinger demo they had with about 1000 KMS. I listened to the Sirius XM stereo blasting in the one in the showroom and figured that the stereo sounded good enough that I don't need to change anything (not to consider other sources sound better), so check there. The car felt reasonably quick, but more importantly had the magazine numbers to back it up. I knew my Mustang ran a 12.92 quarter mile in my city, so I figured a 13.2 would be close enough in the Stinger (stock). I took the Stinger on the test drive and I liked some things like the adjustable side bolsters, the sunroof, the HUD. Infotainment looked modern enough for 2018 and had good features. I drove the car with the stereo silent to be sure it was rattle free, and at least that particular car was. Long story short, I figured the Stinger would be a suitable replacement for the Mustang.
Fast forward not too long and the degradation and flaws reared their head rather quickly. First was the initial paint defects. Second was the nasty 3-4 gear changes. Third was the B pillar door ticking. Fourth was the sunroof popping. Fifth was the hatch clacking over harder bumps. Sixth was the lack of performance (I was only able to get 13.19s 1/4 mile with Map 2 on JB4, I expected nearly that stock). There were likely more things that bothered me, but those stood out the most. The intent on the Stinger was to compromise a bit of sportiness, add two doors, lose a little max performance, to have an overall better car. Unfortunately the issues greatly overshadowed my lofty expectations on the car.
So the question is what would I have bought if not for the Stinger, I think the M240i (which I have now) would be the one. It fits the criteria I want - coupe, good performance, AWD which is nice for winter, a good transmission (although I would have preferred manual with AWD), and "enough" creature comforts and amenities. Would I have bought it ~2 years ago? Hard to say, 65K MSRP is a bit of a tough pill, but right now I saw screw it, I'm not getting any younger and can afford the payments, so I thought I would try. Only the next few years will tell if it was the right choice. The only saving grace is that if it falls short of what I expect, I can give it back when the lease is up without having to justify the flaws to the next buyer.
I don't want to brandish the Stinger. It is great value for money, it does look nice, it does perform quite well. It just didn't hit the mark for me, and I probably had a worse than average one. If mine didn't have all those flaws, would I still have it? Probably. Would I recommend the Stinger? Yes, with a thorough test drive, and knowledge of things you may face.
