nvidia didn't provide drivers directly to end users for any mobile chips, until the current Go 7 series for which they've apparently decided it's now safe to provide them. They want you to get them from the laptop manufacturer, despite the manufacturers largely just getting whatever the current nvidia version was at the time the machine was introduced, and maybe updating them a couple of times, leaving users a dozen versions behind within months. I suppose they may have thought it better to have the laptop vendor be concerned with testing for compatibility given all the high integration and sometimes slight modifications made to notebook systems.
However you can easily get "hacked" driver versions, where someone has simply gone into the INF files included with the driver which contains the product IDs, and added in those for the mobile GPUs, so that the installer recognizes it as a supported chip. They might not be the very most recent, but certainly better than the laptop maker will ever release. Just do a search. I actually did this with my Toshiba with a Go5200 a few months ago. They work just fine with newer versions than Toshiba made available.
