Thanks for all the responses.
In the end, after a check at the garage, it’s just getting new drop links and a wheel alignment for now.
Going by @EvilRacer329’s helpful account of the BC coilovers, they sound like exactly what I’m after. So I might go for those in due course. But it’s probably a bit too eleventh-hour to be making that change right now, and I should probably avoid spending £1600 anyway 
Your setup looks great - just the right amount of lowering and a really nice wheel set. Could you share the type/size of rims and the tyre sizes you have used. I quite like the look of a bit higher profile rubber.
Hey @jwiltshire007, sure thing. They’re Rota Torque wheels at 7.5J17 ET45 on Goodyear Eagle F1 Asymmetric 6’s at 215/45/17. The suspension is BC Racing’s ‘BR’ series coilers, standard spring rate, with the ground clearance set to about 11-12cm (UK speed bumps theoretically max out at 10).
Thanks mate.