How low

[Markmark.123]

I am looking at lowering my gti on springs the day it lowers by 55mm. But with it having gti suspension I am lead to belive it will be 25 mm less than what it says
I am running 18" wheel and was wondering if the archs will need rolling

[StuF]

I have standard shocks with 18'' Monzas fitted running an Eibach Sportline kit with no scrubbing or arch rolling required! 

[56OctyVRS]

I would only lower a car by 25mm and no more. Else you run into issues with speed humps and ramps, which actually impede making progress on roads with lots of speed humps. Plus I think it makes the ride crashy, which is fine if you live where the roads are well maintained and flat. But in the UK the roads are full of potholes and not all that good. I go for comfort now rather than looks. Makes me laugh all the lowered cars crawling over speed humps, scared they might scrape the bottom of the car

[xjay1337]

Eibach Sportline or the H&R Sport springs will be a good compromise.
You'd be surprised how low you can go without running into any major issues on a Mk5, nothing a bit of straddling wouldn't solve anyway. 

[Wash]

I'm on AP coilovers wound all the way down at the front and no adjusters in the rear and it sits nicely. Probably lowered about 50mm+ and it's still perfectly driveable. Gotta wiggle over speed bumps but that's not a big deal.

[th3_f15t]

I run my Bilstien B14 coilovers all the way down at 50mm and no issues with speed bumps, occassional have to be careful pulling up towards kerbs though. Using springs alone will be perfectly safe and reliable for your needs.