Platform? What does it mean? Was: Re: audi coupe

[Adrian Johnson]

>No, the A3 and A4 are on different platforms (the A3 and the Golf share a 
>platform, the Passat and A4 share a platform, although the plaforms may in 
>fact be very similar - as far as I know.  The S3 has a tricked out 1.8T 

What does "platform" mean in this context?

In the past I was told that the Passat and the A4 share the same "platform"
so I thought that meant that they'd have the same basic dimensions,
wheelbase for e.g., but I don't think they do. They are similar but not the
same. 

It can't be just that they share the same engine because that would mean
that Golfs, Jettas, Beetles, Passats, A4s and A6s all share the same
platform because they can all come with the 2.8 V6 engine.

So what does sharing a platform mean?

AD.