UK Ed,

Just performed this same operation over the weekend. The 3rd bolt is indeed a bear to remove, but I found that by using a long 8mm socket combined with a short 1/4" extension and ratchet, you are able to squeeze this assembly between the airfilter box and the distributor cap. The trick is to guide/hold the socket in place with your left hand reaching over top of the distibutor cap and patiently ratchet with limited movement, until loose. Note that I also removed the metal intercooler hose to allow better access and the process will certainly result in scraped knuckles. If all else fails, remove the lower part of the airbox (this may also assist you in not losing the first 8mm socket you attempt to use to the nether regions of the engine compartment :)

Spy