added boost gauge for $12
 

i picked up one of those cheap obd2 bluetooth adapters when amazon had a sale so i got it for $7 :)
then i bought the torque pro app for $5 from the play store. its a crazy detailed app that goes way beyond my needs but it does a lot of cool shit. so now i know my car does 0-60 in 8.6 seconds and runs about 10bar of boost (i hadnt switched to psi yet). i definitely recommend this setup to anyone who wants to know whats going on with their engine and/or needs to read and clear CEL codes.

hurry up and check out amazon while they're still on sale. dont get tricked by the upgraded version, its not any better, these are just chinese adapters that all do the same thing. it comes with a mini-cd of 'software' but dont bother with that, just download the torque free or torque pro app.