Alright! The lowride "guru" (thanks Revs! hahaha) is back!
HMM. Let me try to remember everything: OK.
Lowering springs: H&R + stock shocks looked AOK, not very low at all, much less body roll but the shocks were not great as they would bottom out/bounce.
I bought KW coilovers in the end (through TCCA motorsport Artarmon). They allowed me, in 45minutes, to make the car lower/higher with ease by myself.
First thing to go was the rubber lip under the car. Didn't need it anyways. 2nd thing to go was the engine undertray (!!!). This scrapes into the ground very easily on a 147. It's a silly design really if you look under there. It doesn't protect the sump at all as the design of the undertray has a hole/gap in the middle. I was scraping it into the ground all the time. When I took it off (dealer took it off for me) I never scraped on anything ever again amazingly... even though my ride was so low. I tried an inch lower to have my car as low as your photoshop file (looks too low I think) but then I was scraping my entire exhaust into my driveway so I took off the middle resonator (straight through pipe replaced it) + raised it up another inch again and left it at that.
Tyre wear: the Alfa has non adjustable camber/castor (massive bugger) so your tyres will wear rapidly on the inside. Mine went right through to the tyre wall but the outsides of the tyres were at 80%.
Suspension joints will wear if you go too low (maybe not as GTA's suspension is different to the normal 147, stronger perhaps?) + dealer will not cover you for this.
If you are going to lower it at all I still suggest (especially as it is a GTA) to not skimp out and go for the best: coilovers with damper adjustment. That way you can keep adjusting the height until it's perfect.. looks and comfort.
You can get Bilstein to make up a custom set of adjustables for you. They are in Sydenham. Amazing workshop. So clean, so pro. Next door to Heasmans suspension where they will tune it perfectly. These guys prepare cars for Targa, they also professionally lower exotics all the time.
Some pics of the old low rider for old times sake!
so damn low, ooh la la I think something's going to brake!