Originally the picture of the AC Invalid carraige showed a standard Hard top version.
It seems that now it's a convertible.
I've never seen a convertible version before. Was this a production vehicle or has this been added later? It has a Heidleberg coat of arms upon the door. Was it an export only option? When I was a child these were very common in the UK and seemingly there are still plenty around as they come up for sale quite often, but as I've said never before have I seen a soft top version. They are supposed to be quite scary things to drive at speed, so I can only imagine that with the roof down its a hair raising experience!