I got my car back a couple of weeks ago but I've been away on vacation, so haven't had time to post an update...
In summary, the car runs really great (and sounds amazing) but we had to limit ourselves to 480 whp due to me being on stock tyres. Even with just 480 whp the traction control light flashes now and then on full throttle even i fourth gear (dry surface; highway).
Once I find time (well, money) to upgrade wheels and rubber, we'll bump the power up. Possibly next summer.
However, I have one major issue. Start issues. The engine REALLY struggles to fire. Especially when cold.
My tuner (one local to me here in Sweden) is having a hard time improving it. I have a feeling it could be related to injectors/fueling, but I'm no expert whatsoever. The car had zero issues before the kit got installed alongside Injector Dynamics 1050cc and other supporting mods.
It really, really pains me to start it up. Here's a clip of it. Just before I shot this clip, I attempted another start which I cancelled after 8 seconds by pressing the start button again. It just wouldn't fire up. The second attempt is usually successful but only if I help a little by blipping the throttle. If I don't to this, it'll die right after it fires.
Any ideas? Is this a common issue with large injectors?