[ragtopcav]

I wouldn't use the word 'common' but it is not unheard of. It's a hangover from the Vauxhall cavalier [what did Holden call that I wonder?]. My MOT tester looks for it every year on mine, [1993 first build, not failed as yet]

 

[ragtopcav]

The only one I've done is on a cavalier, I welded with most things in situe, just removed all the carpets and acoustic foam for the task. If I recall I welded a generous patch of 1.5mm thick zinc plated steel. The Saab has a bolt on section sometimes this fails rather than the main panel itself so a 'repair kit' is indeed feasable.

Whilst I had my engine out recently as a matter of course I checked this zone for possible weakness, it looked pretty good, but lower down where the floor meets the bulkhead there was a lot of damaged paint. It was directly under the brake reservoir, over the years spillages from bleeding etc had accumilated into the spongey sound deadener in this zone nad had been slowly eating into the paint. I did a paint repair and cut away this section of foam [the last 2" across the bottom] to prevent a recourence of this.

 

[ragtopcav]

So there aren't any reports of this happening in left hand drive cars in the US?

I get the impression it's mostly RHD that suffer this [the cracks] the thing I've mentioned with the spilt brake fluid can happen to any.