If we said you could own an electric car that offered four-fifths the fun of a 2012 Tesla Roadster 2.5 for less than a fifth the price, you might think we'd been illicitly inhaling gasoline fumes on the side.

What you might not know is how close we are to the truth, and one that comes in the shape of a hugely popular sports car first revealed in 1989. That's right - you can own a first generation Mazda Miata sports EV for less than $15,000, or around 15 percent the price of a brand new Tesla Roadster.

The catch? You have to build it yourself, though a new conversion kit from San Francisco based EV Works means that someone else has already done the legwork for you. EV Miata is EV Works' first conversion kit, developed after rigorous testing and positive feedback from over 500 visitors to their website.

If you have a Miata to convert, you're already half way there. The kit includes all the racks necessary for safely mounting the batteries and the motor and a handy guide to help you put it all together. This kit costs $2,500.

Two battery options are avaiable depending on your budget and requirements. The first is a set of lead acid batteries that EV Works recommends, providing you with around 20 miles of range and setting you back a little over $2,600. If you want more powerful Lithium ion phosphate batteries, there are two options - 45 miles of range for just under $6,000, or more than 60 miles of range for $7,000.

The other components such as the DC motor, controllers, chargers and more can be sourced through various suppliers recommended by EV Works. The bottom line is a conversion cost of around $13,500 for the basic lead acid vehicle rising to just under $18,000 for the highest range lithium ion variant - and these prices are before federal tax credits, if you're eligible. The cost doesn't include the price of a donor car, but if you own a Miata already then you're nearly there!

EV Works claims the kit has been designed with safety in mind, and that it's simple to install with no welding required. If you're handy with a wrench then it could take less than 40 hours of work to convert the car. It uses the standard manual transmission, clutch and flywheel too for simplicity.

And how does the car drive? Well, we aren't lucky enough to have got behind the wheel of the EV Miata yet but based on our experience of the regular NA-generation Miata we expect it'll be a heap of fun. The battery car even accelerates faster than the stock Miata, so expect 60 miles per hour in fewer than 9 seconds, with a claimed 93mph top speed.

Weight is up over stock by 564 lb on lead acid batteries and less than 400 lb for lithium, so it may not be quite as sharp as the regular car, but still light by today's standards.

Interested? If you want to know more you can head on over to evmiata.com or check out the video below.

We're off to hunt the auction sites for cheap Miatas...

[Hat tip to @MikeBoxwell]