This is not my own theory but one that I read on another board...please guys, chime in, because I think it has a lot of fucking substance to it. It's both insane and brilliant, which makes me think it is possible:
The theory that a fellow poster wrote (Ireland Native) is that Walt's glasses are bugged. Think about all the times they have zoomed in/ focused on Walt's glasses over the last few episodes (Including this one). Think about the episode titled, "Bug". Was it merely a narrative on Walt bugging Jesse's car or was there more that met the eye?
When Gus is approaching his car, Walt starts speaking "There you are, now I see you..keep going...", and then Gus slowly stops walking towards the car. Then, Walt continues to speak...Gus then turns to the landscape of the city and begins to scan the area. He then begins to walk away as Walt says, "Why are you leaving...". Does Gus have an earpiece in his ear and is constantly listening in on Walt? I don't know, but this would be much more plausible than Gus simply deciding something is fishy about his car. Remember how Walt proclaimed that Gus is simply 10 steps ahead of him? Walt always has his glasses on, so there is no better place to bug something than his glasses. Also, if you recall when Walt takes a large dose of sleeping meds and Walt JR comes by the house...His glasses are fixed (after Jesse smashed them) as he awakes, again. Now, many, as did I, would presume that Walt JR went ahead ahead and fixed them. How did Walt JR fix them with no car, no money, etc?? This is another argument in favor of this theory (Tyrus or Mike easily may have replaced them). I think the theory is bit out there but I would love to hear feedback on this. He was the only poster who I have seen post about this and a lot of people were taken aback by the plausibility of it.
Now, the small argument against the theory (Could be many more based on responses). Is it possible to bug a pair of such thinly framed glasses?\Let's get this discussion going.
Cheers
Tomer