To be fair though Mark there isn't a set way to do things.
There are possibly some corporate guidelines and some companies will choose to follow these and others won't. And of course it will depend on the industry.
The company I work for like to put ideas out there to customers and invite suggestions and feedback and work with them to develop solutions that are being highlighted and requested. When the prototype is out there, customers are invited to see and use it. When the finished product is planned, all the customers know straight away so they can make decisions a long time before they can buy it. The result is that we consistently beat records, keep customers interested and involved and market things to suit. And it is a much bigger company than SEAT albeit in a different industry.
Regarding cars, some are announced and or detailed by the manufacturer way before they are ever available. Of course strategy will play a part in that too.
For example this may happen (probably it won't but who knows). Lets imagine Ford release info in early 2015 about a Focus RS 320bhp and 4x4. That could potentially eat up lots of potential buyers for a planned
MK3 Leon Cupra R in late 2015 with 320bhp and 4x4. At that point, it may be strategically smart for SEAT to "leak" information of a 320bhp 4x4 Leon Cupra R to make buyers think