Calling the usual 205 scooby crew
 

It seems a lot of 205 owners are putting 309 rear beams on their 205's.

In one respect I can see the reason for this as it would give a wider track and therefore give more stability. But would a wider rear not make them less nimble on the corners??

Its the increased torsion bar and arb thickness thats the key, the extra 50mm track is just a bonus.
It helps stablise front suspension increases in spring rates.
Most 205s owners prefer the 309 beam, but I'm sure its more edgy, not driven one with it on.