Left-right wobble at low speeds
 

Sometimes I wonder if it is just my imagination, or if it's simply due to my low profile tires bouncing around on crappy roads, but at speeds of 40 mph or less, I detect a kind of left-right wobble. I can actually feel my head move left to right. However, when I hit the gas and pick up speed the wobble seems to fade away.

Not quite sure what to check first. Had an alignment and new front tires about 2 years ago. The mechanic mentioned that my 'camber was at its limits and would need to be replaced eventually'. So, I guess that is what I would suspect first. Have checked and adjusted tire pressure. Do not notice any extreme wear patterns on any tires, although it seems the outside of my front tires appear to be wearing out faster than the inside.

Any advice welcome. Thanks.

It's what is commonly referred to as "tramlining".
Usually when very wide tires are fitted, and often worse when tires are cold.

I do have the wider tires on the 4.6is. And I have noticed that it the wobble seems to be the worst when the tires are cold. Hmm. So annoying. Thanks.

It can also vary in intensity between tire brands/tread designs - some don't suffer tramlining as much as others, if at all.
My 4.8is has near-new (20-inch) Toyo Proxes ST-2, and so far there's been no deviating at all, either hot or cold.
By comparison, the 18-inch Goodyear Eagle F1 Asymetric's I had on a previous BMW, always used to tramline when cold, but performed superbly once warmed up.
I've heard that Michelin Pilot Sports are also bad for this.
Regardless, I'd suggest you get an alignment check done, just to make sure everything is within tolerance.

Wheel balance too perhaps? Especially if it's more of a "shimmy" than a "wobble"