Hi MJ, Thanks for your reply. You are correct that it is not the bar I am worried about but rather buying a box that will foul the rear spoiler when the boot is opened. I also don't want to have to worry about opening the boot gently as any passenger could open the boot and not remember to be gentle and I'd worry that could potentially cause damage / cracking to the spoiler to occur. The rack mounts were installed up until May 2013 I think so they will definitely be on the 2009 model. I have heard of the water ingress issues but I am sure I can avoid this with common sense, a bit of time, and maybe some silicone sealant and possibly some lithium grease or similar.
Hi Lewie, I have looked everywhere for the information I'm after but I cant find it. I have found pics online and after making some rough calculations scaling them to my own car I reckon the front bar is around 1200mm from the open boot, the rear bar is around 400mm from the open boot and the bars have roughly 700mm centres.
Price considerations mean I am looking at Thule's cheaper range of boxes - the "Touring" series. There are 5 boxes in the series. three can be discounted for being too long, too narrow (I want minimum 600mm wide), or both (600-Sport, 700-Alpine, 780-L) Leaving me with two options, either the smallest one or the next one up (100-S or 200-M). Based on my guesses above I believe that I should be able to squeeze the 200-m on without it fouling the boot lid when open (I hope I am right).
There are a few reasons why I am not considering the Thule bars: The 09 fiesta has a specific mounting system and a specific rack specifically for the car. Why choose something different? The Ford system is cheaper I am sure (just picked up a new one for under £100, either system will likely become redundant if I get a new car anyway). Ford system looks better. I have a 3 door fiesta so there are no rear doors frames to fix the rear bar to. I don't really like the way it clamps onto the door frame anyway. The clamps seem to foul the door seal. I don't like Thule's solution for three door cars (see Pic below), looks like a bodge with both clamps on the front door and the rear bar just resting on top of the roof. I have also heard stories about this design coming loose!
Once I have all the bits I will update this thread with the confirmed detail
Both images from: http://www.ford-accessories.co.uk/fiesta/2012/transportation/roof-transportation?intcmp=other:acc:pdp:prod-list-view::select-product-group#
above image from: https://www.gumtree.com/p/car-replacement-parts/ford-fiesta-mk7-roof-bars-roof-rack/1187153065
Thule Touring 200-M Box:
More information here: https://cdn1.static-tgdp.com/assetloader.axd?pimid=634201&id=562710&brand=Thule&market=GB (link to manual download)
Web page: https://www.thule.com/en-gb/gb/cargo-carrier/car-top-carrier/thule-touring-m-_-634200.