Sounds too good to be true. On the other hand, the author could assume your scavenging skills and good fortune might make up the difference-access to a salvage yard/scrapheap, desulfating old used batteries for 6-15 months of extra life, access to a well-stocked machineshop, plenty of skill with electronics/mechanics, etc etc...
Probably not. Then again, look at the Forkenswift and the Nemo, both on this very forum-so not completely impossible for a low-speed, short-range EV (note that the Forkenswift is improving in both departments, but extra funds are playing their part). But so far these are the exceptions proving the rule-and the Nemo is a motorbike.
Bottom line-how much money do they want you to give them for the Book/DVD/whatever?
And yes, you can build an EV for under $300. Buy a cheap DC motor off of Ebay at 24-36V (heck, check out vintage car parts and grab a 12V, 25-40A generator and overvolt it) pick up a cheap Motor controller and charger as well, rescue a bicycle from a local dumpster, pick up an extra chain and a gear, grab a few used batteries and celebrate your new EV! You won't go fast or far, but it runs...
So yeah, it can be done-but this guy's talking about full-sized cars and better-than-average performances...i'm a little suspicious.
Unless you have some money you don't want to keep, i'd pass-there's just too many wonderful posters willing to give you the info for free. Ecomodder for one, and also:
DIY Electric Car Forums - Electric Vehicle Build and Conversion Community One of my favorite resources, aside from here!
Oh, and that cheap EV I mentioned above? Mine. 1970 VW generator running at 24V, no shocks or springs, and it's wishing I had a job so I could do more than test it with my Dad's borrowed Dewalt tool pack.
Cost is $130 so far, and $60 out of my first paycheck will get some cheap LAs to put it on the road...beats sinking $900+ I don't have into a kit from China, right? But no, I can't imagine doing a full-sized car conversion on that, not at all.