Well if a flat RTA response sounds like poo why would you want to start there if your looking for SQ? I think you would be quite suprised how much output your subs produce OVER the rest of the system. Getting perfectly flat is not an easy acheivement, keep in mind car acoustics are not friendly
For SQ, its your ears that you have to impress. For everyday use, I would start with the EQ flat and adjust from there. Play around with it, there is no real wrong answer (aside from a V or the smiley face is popular too....LOL) Bob, has more expirience in actual tuning so he can probably offer some good advice and probably can point you to some trouble spots the Contour may include