Lamborghini Gallardo

[NightEye]

You probably got a hidden poly somewhere that stretches up your mesh (hence the black spots). Try to find it, and if you can't I can always help.

Btw: press 'd' and turn off 'Show Cages'. That way you can see your mesh a lot better when smoothened

Looking good sofar

[dppd69]

Agree with NE.
Select all the quads you can see in the critical area and press "-" (dash). This will hide them and reveal the guilty . then simply delete it (them) and press "\" to have all your polys back in display...
As for the Subpatch vs CC, I recommend to use Subpatches. Infact the CC will generate a way more dense mesh (1:4 ratio at Level 2, 1:16 at Level 4. 1:1 when SubD Level 4 and CC Level 2).
To verify it, set the same level for both, draw a cube and hit TAB. Then press CTRL-d to "FREEZE" the model and hit "w" for statistics (with Polygons enabled). You can easily count the polys generated by the two SubD types.

Hope it's clear enough,
Dario