One word with what is wrong, Sony. They are one of a few (the others are Toshiba and Panasonic I believe) that won't allow for the use of reference video drivers from either Nvidia or AMD, hence why modded INF's are required to get them to install.
As far as modding the INF goes, not sure how well Mobility Modder will work with the latest drivers, but seeing as it hasn't been updated in over a year it probably doesn't work (or work properly) with the latest drivers. A better option of modded Nvidia laptop drivers is to get them from here,
NVIDIA & Laptop News | Latest NVIDIA drivers and related news | laptopvideo2go.com
where they come with the INF already modded.