Subaru are now offering the characterful STI with an upgraded engine and a satellite navigation system as standard, with no increase in its on-the-road price of £32,995. So what’s the catch? Well, as with all good offers this one’s only available until June 31st 2011.

The revised 2.5-litre Boxer 16-valve turbo engine now produces 315bhp (up from 296bhp), but the increase in torque is even more generous – up nearly 50Nm from 407Nm at 4000 rpm to 450 Nm at 3400 rpm.

The power upgrade which has been developed in-house at Subaru UK, is also covered by a Subaru UK warranty. The increase in performance now makes the STi a sub-five second sprinter from 0 to 62 mph – recording a very credible time of just 4.9 seconds.

Subaru's STi now sports 315bhp - for a limited period

In addition to the engine enhancements, STI’s purchased within the qualifying period will also receive a Pioneer sat nav system fitted as standard. The system is touch-screen enabled and features Bluetooth and iPod connectivity. The screen can also be detached and connected to a laptop via a USB port for easy downloading of information.

As before, STI’s come as standard with symmetrical AWD, keyless entry and push button start, hill start assist, climate control, SI-Drive, leather Recaro seats, 18 inch alloy wheels, remote locking, satellite tracker and cruise control.