Here's a DFF exporter I wrote myself. Supports GTA III, GTA VC and GTA SA models (PC only). The binaries were developed with the 3ds max C++ SDK and can be accessed through File > Export.
DOWNLOAD LINK
(This is temporary. Files haven't yet been approved on gtagarage Updated on 13 May 2012 to fix light export problem pointed out by blaster_nl).
Sample screenshot:
(The vehicle in the screenshot has already been released & is available at gtainside. )
This tool doe