A bit of an update.
No real drama, as I was driving over a speedbump on site and car made a strange noise from the front and I bottomed out (never done that before). I carried on into the car park, jacked it up and took the wheel off- hey presto, snapped spring. Have a few pics but can't attach them whilst at work.
Have phoned Fensport, where I bought them and they said they've never heard of these breaking, couldn't do anything warranty wise (and doubted Eibach would) and quoted me £280 for a new set.
I then phoned Eibach UK and found out they have a 5 year warranty. Back to Fensport and found out I bought them on 13/04/04, which is one week inside the warranty!!!
Back to Eibach and they say if I can prove purchase was made within 5 years, they'll provide 2 new front springs free of charge (hopefully that will include fitting too)
Need to wait until the US are up and in work to find out what to do next. Fingers crossed