it looks like you have asked for the one NSX that is not actually tuned up. Have you tried any of the other tunes for NSX's on it to see if they work out? Honda and Acura cars of the same model are identical and variances in types like S and R, in GT6 are generally small and tunes can sometimes cross over.
Just about every garage here has at least one NSX tune for the Type R, Type S, or Prototype, or the HSC which is he next gen NSX.
You can click the link in my sig to go directly to my database here at GTP, or check out, Exeter GT Tuning Bowtie's Speed shop Motor City Tunes Tuning Garage Links