Isn't it a Sonnet? Well, the License Plate shows half the story 
SAAB**V4 which means it had the Ford Taunus V-4 engine.
Other than that, it's one of a very select bunch of cars that had Two Stroke engines. This and the NSUs had 2-Strokes. The one in this had 3-cylinders and 748 c.c.
History has the odd habit of repeating itself. The V-4 unit in the Sonnett 1, which you've shown, comes from Ford. It wouldn't be till the early nineties that Ford would start experimenting with 2-Strokes again.
Their Two-stroke would run in a prototype based on the Ford Taurus in the US. Ford designed the KA to receive a 3-cylinder 2-Stroke very similar to one in the Taurus.
Unfortunately, emissions regulations changed and they couldn't make the engine pass the tests. Frantic for a new engine, the KA engineers could only fit the old OHV pushrod Kent unit (now called the Endura-E) because the engine bay was so narrow. This engine came to life in 1959! A 1.3 with 65 BHP.
Here's an interesting Saab 2-stroke project:
http://en.wikipedia.org/wiki/Saab_Monster
Cheers!
Sami
