If you don’t want to wait until the recently unveiled 2012 Astra OPC goes on sale then you might consider Senner Tuning’s most recent upgrade program for the Astra J.
In this case the German hatch will look sportier thanks to custom body elements such as a matte black front grille, a roof spoiler, a front spoiler lip, revised side sills and rear diffuser plus the built-in wheel-tire combination comprising from 19 inch Alutech rims wrapped in Vredestein Ultrac Sessanta tires size 235/35R19.
In terms of performance however the Senner Tuning Opel Astra is still 115 HP from what the OPC version has to offer, as the standard figures of 140 HP (103 kW) and 200 Nm of torque are dialed up to 165 HP (121 kW) and 250 Nm of torque via a remapped ECU and a sport air filter from BMC.
The Senner Tuning Opel Astra is also equipped with a new exhaust system featuring 140×90 mm stainless steel end pipes, a power converter for the electric acceleration pedal and red painted brake callipers.
The price for all this is 11,900 Euro, which should be considerably less than what the OPC version costs once it becomes available on the market.

Source: Senner Tuning