wobble at low speeds

[Will_w202]

So I changed my wheels and tires (to 17" AMG splitspoke and Potenza RE950s) around Thanksgiving, and the low-speed "hop" I had for months disappeared. I attributed it to out-of-balance tires, since I did have a shimmy at speeds above 45 or so as well. Well........

After snow was forecast last week, I put my old wheels and tires (the factory 8-hole wheels and OEM Continentals that came on the car) back on for winter duty. I used a pneumatic jack and jackstands, and a torque wrench. I didn't check the pressure as I figured it would be adequately low for snow use after sitting in the garage for 2 months. I drove to work (city and highway) and the hop was back! Worse than before though, and now the whole car was shimmying and I could observe the hood ornament visibly moving side to side at low speeds. So, on Friday I got the tires balanced (I had already installed them in rotated order)

After balancing, no more bad shimmy at highway speeds, but THERE IS STILL A HOP! Why, don't know. Here is what I DO know:

1) The shop that installed my AMGs, I think, overtorqued the lugs and helped warp the rotors (or for some reason, I developed a shimmy when braking in succession after about 1k post-install)

2) I used to feel the car hopping at low speeds, but since the rotation it hops AND when I steer, the car gyrates from side to side. That tells me that, in all likelihood, if their is an offending wheel or tire, it was on the back and is now on the front, and best I can tell it is coming from the front-right.

3) This behavior got noticeably worse after the tires sat apart from the car for 2 months, though it is not NEW behavior, rather same problem, just worse

4) If a tire or wheel were out of balance, out of round, or bent, wouldn't the person balancing the tire notice the problem?

For the record, I have never hit anything to bend a rim, so if it is the rim, it's a Starmark-certified bent rim.

Oh, and when I presented this problem late last summer, the dealer said they could not duplicate it. HELP!