This is MK2 (pre facelift - 2007).

Upon closer inspection, the front windscreen roof area develops small rust and its creeping.

Should i be worried or is it mild ? I like to keep this great motor a couple more years.
Any tips or tricks or experiences? Looks hard to fix without taking out the windscreen. Not flaking or lose pieces yet.

I've been battling with rust caused by stonechips in the area between top of windscreen and sunroof on my 02 Mondeo, that's bad enough. You're gonna find that creeping stuff is worse than it looks once you start stripping off the paint. 

doesn't look good, and you can bet your life it's worse where you can't see it than where you can. And if you start trying to do something you'll probably wish you had never started. 

To be honest if it was mine I reckon I would leave it how it is and hope it does not start leaking rain into car if I did find it started leaking I would probably try to plug it with a load of silicon sealant.

Don't know how easy it is to get the rubber strip bit out. could perhaps pull that out and then remove loose flaky rust and then put a thick layer of hammerite on it. that might slow it down, but I don't think you will eradicate it.

 

I had a similar thing in the same place on my first car, a Nissan Micra. As previous posts have said, once you start picking away at the paint, it will start flaking away and you'll wish you never started. With my Micra, I used a product called cure-rust (It might have been spelt differently but it was something like that). This is a very thin, milk-like liquid which you can carefully brush into the exposed, rusted area (and it will seep under the seal and possibly even some of the bubbled paint as well) and it stabilises it, so that you can then use your usual paint to paint over it. In my experience, this probably won't be a permanent fix and the rust will eventually win but this should buy you some more time.

10 hours ago, Dark Andy said:

 I used a product called cure-rust (It might have been spelt differently but it was something like that). This is a very thin, milk-like liquid which you can carefully brush into the exposed, rusted area .......

This is the product you need. I've owned my fair share of rust buckets in the past, and sadly I can tell you the only way to fix this properly is windscreen out, treatment, and respray. The car is probably beyond economical repair so I would just run it till it stops getting MOTs...

 

I thought the Ford Focus was supposed to be galvanised ? That was one of the reasons I bought one ! Mine is also going a bit in the same area, though not as bad as yours. What worries me is it'll spread under the windscreen seal and be unstoppable, plus it'll leak obviously.