I'm off to screw mod my Dturbo!

Its funny though, exhaust and filter, even with more fuel and boost wouldn't see me 135bhp. You are being over optimistic there mate.
I've just looked and according to carfolio the lupo gti has the following -
Max. output
(DIN) 124.7 PS (123.0 bhp) (91.7 kW)
@6500 rpm
Max. torque
(DIN) 152.0 Nm (112 lbft) (15.5 kgm)
And if your car is the 1.4 FSI its this one yes?
Max. output
(DIN) 104.4 PS (103.0 bhp) (76.8 kW)
@6200 rpm
Max. torque
(DIN) 130.0 Nm (96 lbft) (13.3 kgm)
@4250 rpm
How is it going to get to 135bhp, when the GTI makes only 123bhp in 1600cc form?