IKEA has shown that if the price is right, people are willing to get their hands dirty and put their own furniture together. So why not carry this model over to other industries -- locomotives for instance? The Tabby from OSVehicle is one such attempt at making cars a commodity one can construct at home... if you're brave enough to drive around in something you put together yourself.
The only issue with the Tabby is that it's not as cost-effective as buying a used car. At between €4000-€6000, the compact, dune buggy-like vehicle could hardly be thought of as a steal. In fact, if you want the Tabby to look like a real car, you'll need to get the panelling made yourself, adding an extra expense.
On the technically side, you get the choice of a four-stroke, 5.5kW engine, or a hybrid model with a 15kW output, with the top speed varying between 69-149km/h.
I don't pretend to understand what the "open source" aspect is -- it's not like they're allowing people to collaborate on the design, or any aspect of the business, in a way you'd describe with the word "open". "Modular" might have been a better option. Going by this press release, it looks like it's trying to establish some sort of framework for people to distribute and sell DIY cars, but it doesn't do a good job of advertising this philosophy.