Stage 1 Software:
X5 Series*::*X5 4.8is (E53) 2004-2006*::*Engine Tuning*::*Performance Engine Software

Stage 2 Software:
X5 Series*::*X5 4.8is (E53) 2004-2006*::*Engine Tuning*::*Stage 2 Engine Software

Stage 3 Software:
X5 Series*::*X5 4.8is (E53) 2004-2006*::*Engine Tuning*::*Stage 3 Engine Software

Only purchase Stage 1 software if you don't plan on doing any other Dinan upgrades. Do each other stage as you plan to add CAI, TB, etc.

__________________
Jeff
Current:
'07 Jeep Wrangler
'06 BMW X5 3.0i

Former:
'12 WRX; '08 WRX; '06 BMW X5 4.8is Dinan S1; '02 BMW 530i Dinan S2