Got mine off a user on here back in the days when there was a parts for sale section on here. Was still in the sealed packaging so basically brand new, think I paid £50 for it, result

Pretty sure Awesome GTI sell them, you could try there, alternatively if you have a vice then you could just get Powerflex or Superpro bushes and change the ones in your existing mount, that will give the same result. Either that or get another standard one and change the bushes in that, then just swap it over for your current one.
It does
help reduce wheel hop under hard acceleration in low gears but personally I wouldn't be beasting it in first anyway - the turbo is quite small which is nice in one way cos it spins up very quickly, giving good response. The downside is that when it hits the intended boost level the ECU can't stop it accelerating quickly enough so you get a boost spike, the K04 turbo is known for it. Too much boost low down the range in low gears isn't good for the conrods so don't go too mad low down the range.
The suspension I got is called a 40/40 kit but in reality for a Cupra R you get 20mm lower than standard - the reason for that is cos the Cupra R is already 20mm lower than the standard
mk1 Leon. I wasn't looking for a big drop, I think really slammed cars just look broken, but then I'm a (relatively) old git so that's just me

I just wanted better ride quality and handling really, coilies will give you more adjustment options but I'd just end up fiddling with them. Bizarrely I find I scrape the splitter and undertray less now it's lower
I've stayed away from spacers, a guy that was once a member on here warned me off them. Spacers increase the shear forces acting on the wheel bolts, I know the risk is small but I wouldn't fancy snapping a bolt while on a twisty B-road. I found that once I'd changed the suspension the wheels seem not to sit as far back inside the arches though so change that first and then decide if you still want spacers. For me, the car has to be safe, be reliable, work well and look good, in that order. Like I said, I'm an old git
