09 is different body, 25mm with 21's is not confirmed, espercially if you drop it later...
"Hum... this is assuming that the 06" and 09" are built the same way, right? "
this is assuming the OE stud length is the same, which it is... like I said in the other thread, nissan is stingy on there stud length... reason being that the spare is a stamped steel wheel & for the closed end lugs to still work with the spare they have to leave extra depth there... the spare is much thinner at the lugs than the aluminum wheels. there is no way the 09's are using shorter studs because the studs on the first gen are about as short as you can safely go... if you go with longer studs you MAY need to use open ended lugs for the spare only, & even then maybe not...
we used 15mm longer studs on soons ride, & guess what... even with the 15mm longer studs the lug nuts still fit fine even when the spacer was completely removed... just to show how much more depth the lugs have compared to the available stud length.... & yes, I'm talking with the same exact OE lug nuts you have & the same 21" enkie's you have...
I keep repeating myself but I'm trying to get you to see wtf I'm talking about...
dude, you have 3 choices....
1) replace the studs with longer studs... (best option)
2) go 15mm-20mm 10 stud design & cut your stock studs & always have to run the spacers...
3)go with 25mm 10 stud design that'll bolt right on
trust me bro, I'm not guessing here, I've done these several times already, I'm not giving you opinion I'm giving you facts & tying to help you

even the dealer doesn't necissarily know what there talking about... weren't they the ones to say you can use 10mm 10 stud design? that's not possible...