Whilst the sharing of "destination chargers" or "superchargers" would initially seem advantageous to the big car manufacturers e.g. audi/toyota/mercedes/bmw etc, there are a number of reasons why i, to much dismay, don't see it happening. at least till 2018 or so:
1. This is the key point: the competitive advantage of current big car manufacturers e.g. toyota/audi/BMW/mercedes are ALL in the drivetrain. Their absolutely most valuable tech knowledge and production abilities are focused on the engine and the tranmission box. THAT'S IT. Not the suspensions, not the safety features, not the interior. JUST THE ENGINE AND THE TRANSMISSION!! most other components have much less tech requirement to produce, and are often sourced from 3rd parties whilst the engine and transmission remain absolutely crucial to them*. this explains the strong aversion against developing EVs up until recent years when tesla (and partly nissan/chevy etc) really changed up the game. Big manufacturers producing EVs mean a relatively simple motor (which can't let them make themselves stand out amongst others), and battery tech (which they're a very much behind). Asking a company to give up its current leading "tech", their core competitiveness in internal combustion engine + transmission, in order to pursuit something they're secondary in and/or see no way of producing a strong competitive advantage even in the future... what company would actively invest/encourage something that puts them in an overall disadvantage? it is mostly becuase of tesla that the notion of producing EVs has gone from "lol" to "reluctant but cannot be dismissed". BMW obviously has done quite a bit more with their i3, but look at its funcationality on a day-to-day basis compared to what you can get at similar price point.
*TESLA's supply chain production model has been shunned by the big makers a lot while back, realising they could save costs and have better focus to only concentrate on the engine and trans whilst outsourcing the rest, mostly.
2. whilst EV production numbers overall are ramping up from "negligible" to "almost noticable", currently they barely scratch the surface in the total number of vehicles sold by the big makers. An alliance in charging network at this moment is just commiting resource to something they aren't good at/profitable from at this moment, whilst the biggest winner out of having this alliance at this moment, is just tesla, who will directly benefit from it IMMEDIATELY.
3. This alliance would also paint a clearer roadmap for tesla's future, i.e. much more bargaining power they'll have with shopping malls/ building management/ carparks to install more chargers everywhere, directly improving one of the major bottleneck of their sales number in places like HK. audi/BMW's executives are gonna have fun justifying putting resources into their direct competitor (in the luxury sedan market no less) pockets at their next shareholders meeting if they do.
4. in most other places outside HK, people are expected to install chargers without jumping thru hoops that we do here dealing with management companies being pricks, which means chargers are mostly installed at home, and "destination chargers" and superchargers are largely complimentary rather than being the chief method of recharging. so this proposed alliance would may only be possible/conceivable in localities that face the preculiar issues that HK EV owners face.
imagine the difficulty of audi/BMW's hong kong branch pitching this idea of an alliance to their global HQ, and being strategically out of sync with the rest of the entire company? work WITH them!? they're our competitors!! the top level executives always make decisions that impact the entire company, and they're rather unlikely to put a small exceptional clause (of allowing a HK charging alliance) in the grand scheme of things.
5. further more, how you're going to develop your EV now as a big car maker is crucial. what battery tech are you going to go with? tesla battery tech are the most "tested and proven", and it has an open patent, so you're going to go with that? and give up all your negotiating power in the process by relying on tesla/panasonic to produce the MOST crucial component for your EVs? or would you rather play catch up, and pour resources into developing your own battery tech? lets say, out of 6 big makers, one went with the tesla/panasonic tech and the others successfully produced their own batteries for their EVs. you can't assume ALL the different batteries receive charge the same way to keep them at optimal performance/ life right? some may prefer a <70% SoC at all times, some may NEED a super high voltage charge to keep them healthy, whilst some may need a low voltage crazy high amperage charge, such that the hardware of tesla's chargers just aren't compatible with its optimal way of charge. so why would you join alliance with tesla when your own EV can't perform at its best when using these chargers? because tesla sure as hell aint revamping their hardware specs for you.
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TL;DR the ideal of an alliance seems a lot more bleak when the business aspect is involved. i apologise for dumping a wall of text, when most of it isn't even HK focused. just thought i'd share a few opinions that i have. as a token i'm sharing this comic with you, take from it what you may