The pedal placement on this car is not ideal. The throttle pedal is too far aft relative to the brake, so unless you're braking hard (e.g. from hard speed), you're never in the right place to easily blip the throttle with the side of your foot.
I suggest getting a set of ultimate pedals, or even getting just their throttle pedal as it bolts on top of the existing pedal and brings its face closer to the same plane as the brake's. The other thing with this car is that the drivetrain has very low inertia, which is great, but when heel and toeing, requires a little more revs than one might give in another car.
For reference, in my S2000, I heel and toe just fine with the stock pedals, but on the M3, I went with a set of ultimate pedals and it made a huge difference.