Before you go around spending more money on noise reduction, consider what should be acceptable for a front wheel drive Suzuki. If it bearable, it's perhaps best to live with it.
Secondly did you ever check your wheel bearings?, they are equally responsible for the unpleasant noise. Can be easily checked by letting your car roll on high speed and disengaging the transmission (let it run in neutral) if the sound disappear or reduces significantly, consider replacing them ASAP.
As far as the Liqui Moly product for transmission noise reduction is concerned, it was a complete failure on my lancer's transmission - Other PW members may have a different opinion / experience.