ARock, Is this what you are looking for?
http://www.mobilefun.co.uk/product/10356.htm
This is the Car Holder HH-12 that affixes to the windscreen

The difficult component to find is the Mobile Holder CR-86 which holds the N800 and screws on to the Car Holder HH-12.

Yep, Im looking for that and the part to which you can mount the N800 - or any alternative holder there might be.

At this moment I do not have any part of the N800 holder as the Nokia here in Finland does not sell that or any part of that. Or actually Im not 100% sure whether they sell that thing which goes to the car wind shield but in any case that does not help much as they are definetly not selling the actual N800 -mount that goes into the wind shield part. Ive checked the situation with the Nokia Flag Ship Store and they said that no can do. Not even as spare part sales.

I actually referred to the same page you did when I was looking for the holder parts here in Finland by emailing various suppliers and to my query all the local suppliers said that youll just have to buy the Navicore kit in order to get the holder (i.e. the 2 parts). Sad but true, as one famous song says

Now Ill just have to see what comes out of the negotiations with this one store who - apparently - imports from Sweden. As said before, they were of the opinion that the holder they have is N800 compatible and it did look like it would be... lets see.

There's a lot of cheap car mounts on ebay which claim to be good for the n800. I cannot say if they actually are...

For whatever reason Nokia just won't make available N770/800 accessories to be purchased separately. Just look at the stylus mess for starters.

Refer to the retailer link above you will see Mobile Holders for a whole raft of Nokia phones, so my not for the IT's?

Things get lost, broken, stolen, N770 owners upgrade to N800's, so why can't we buy these things?

My words exactly, its just unbelievable. The guys buying the Navicore kit better take very good care of their holders

I mean I never ever thought I would run into trouble by buying the navigation kit parts separately. I bought the N800 as second hand and I already had the GPS thingy from using it with my Nokia mobile so obviously I just bought the Navicore DVD and thought ok Ill just buy the car holder next and thatll be it... ohh how wrong was I there!

And besides us, I do believe theres a whole bunch of other people out there without the Nokia car holder at the moment...

Thanks, have to check that out if my current plan fails!