My post on Model 3 competition will come later in my series as I plan to lay a framework to understand the competition.
However, I'll give a quick preview.
Many people group EVs into one category or separate EVs from ICEs. However, I think the correct way to look at it is to look at the current market segments of cars and just place EVs under the current market segments and not to treat them differently.
That said, the Model S competition is any premium large luxury sedan regardless of its fuel source.
Model 3 will go after the luxury compact sport sedan market, where the current market leader is the BMW 3 series (others include Audi A4, Lexus IS, etc).
Currently I haven't seen any auto maker (besides Tesla) reveal plans for an electric vehicle to take on the market leader of the luxury compact sports sedan market.
In order to understand the motivations/goals of current EV manufacturers (besides Tesla), one need to look at and understand the Prius market and the city car market.
The Prius market (high mileage mid-sized economy car) is what has motivated most EVs to date. The Leaf/Volt were cars that were intended to take market share of the Prius market. Even the BMW i3 was intended to go after the Prius-type market or rather I should say the luxury Prius market, looking for Prius-type buyers who wanted a bit more luxury. The big challenge of current EVs in the Prius market is that of range. Further, the Prius market is getting crowded with new high-mileage hybrids like the Accord or Camry hybrid.
There's also the city car market of very small cars (ie., Fiat 500) where some EV makers are looking to take market share.
Most (if not all) EV manufacturers or going after one of these markets - Prius, luxury Prius, or city car.
No one is going to say the Leaf or Volt is competition to the BMW 3 series. Nor are many people going to say the i3 is competition to the BMW 3 series. The BMW 3 series is just in a different league in terms of performance, handling, etc.
So in the same way, the Model 3 doesn't really have any electric car competition (because no auto maker is trying to make an EV that's better than the 3 series at the same price besides Tesla). Rather, the Model 3 competition is the BMW 3 series market.
There are going to be some auto makers that try to make a 150 mile (or even 200 mile or more) range EV. And people are going to clammer that it's competition for the Model 3. But chances are is that 150-200 mile EV from another manufacturer is not going to be in the same market as the BMW 3 series. Rather, it probably will target the Prius-type market of high-mileage mid-sized economy car which is totally different than a compact performance sports sedan.
Also, I don't think any auto manufacturer thinks it's possible to make an EV that's better than a BMW 3 series at the same price. And because they don't think it's possible, they aren't even trying to make an EV as a BMW 3 series competitor. Rather, they're content with trying to pluck away at the Prius market and city car markets.
So that's what is so revolutionary about the Model 3. It's a car that most auto makers think is not possible (a 200 mile range EV at $35k with performance/handling/acceleration as good or better than the BMW 3 series).
So, when you hear about people talking about the next great electric car by an auto maker, you should ask what market segment is that EV shooting for? If it's not aiming to be better than the BMW 3 series at the same price, then it's probably not going to be competition for the Model 3.
A final note, I personally don't think it's the right time for an electric car to displace the Prius in the high mileage mid-sized economy car market. It's going to take more time for battery costs to drop. But when it's the right time (ie., maybe 2022?) I think Tesla will release a compelling vehicle in that market, ie., the Gen4 vehicle (which I'll talk more about in my series as well).
These are all good insights, though I would make one modification--a lot of the EVs out there now aren't trying to take market share from anyone. They're built purely to satisfy regulatory obligations, and the automakers take a variety of steps (from limiting the number of markets in which they are sold to disparaging them in public) to ensure they sell no more than they have to. The Fiat 500 fits into this category, as Marchionne has candidly acknowledged.
But you are correct that the popular press still misperceives "EV" as a single category in which the same people cross shop. That's why we see comparo tests like the one in C/D that put the Focus EV and Fit EV up against the Smart EV and 500 EV. Almost no one would cross-shop the ICE versions of those cars, so why should the EV versions be seen as serving a single market?