It sounds '80s.  It's dance-pop and I found it on Limewire.  The file says it's a Stacey Q song, but I doubt it.  I checked everything Stacey Q and her band SSQ have done and there isnt a song called "I Want You Now" on any of their albums.  Perhaps it's something that was on a movie soundtrack.  I don't know.  There's a few rare unreleased SSQ songs out there but this definitely isn't in that mold as SSQ were more synth-new wave (plus I believe I've heard everything SSQ has done anyway) and Stacey Q's stuff is more dance-pop/HI-NRG.  I have Stacey's Q first two LPs Better Than Heaven and Hard Machine and it definitely isn't on them.  Also I've searched relentlessly on the web and have found nothing, including the lyrics.  It's unfortunate because a title like "I Want You Now" is so generic.

Some of the lyrics

Let's do this!  Please baby, please baby, please baby (repeated) (In a "Two of Hearts" kind of way)

Maybe it's because you're irresistible

You'll soon come, I could make you mine

Maybe it's because I'm so in love with you

If you only knew, how I want you too

Ohhh, Cover me with kisses and caresses oh baby can't you see that I'm your star

(chorus)

I want you now, come and share my love divine
Desire's killing me
I want you now, tonight is burning now
I want you now need you now, please baby please

Does anyone know??  This is driving me crazy!
 

don't you think we connect and two of hearts are the same song?  Seriously, listen to one and sing the other and you'll find that its the same beat. 

BTW don't know this song what about early Samantha Fox? She sounds SQ like on that first album.