IMO it's not about making it more difficult, or adding a selectable difficulty option. GT needs a huge overhaul. The whole "chase the leader from the back of the pack" thing just doesn't cut it anymore. The offline racing in GT now is more about acquiring cars than it is about proper racing. The default back of the grid position, the flawed rolling start procedure, the rubber banding, the amazingly thick AI, etc., all needs a serious re-thinking. There's no racing in offline GT6. Races are basically just time trials where you have to dodge some slow cars along the way.
No amount of adjusting your car's performance to make things more difficult really gives you proper racing. Yes it can make it more difficult, but with the woeful AI and the rubber banding... you never get proper competitive wheel to wheel racing, where maybe you've spent two laps following a car trying to get close enough to set yourself up for a big move down at turn [whatever], braking as late as possible and holding on around the outside of the turn to set you up for the inside line of the next. Instead, you'll spot the AI car in the distance, within a few turns you'll be right up on it, and then not long after you'll just cruise past. The only competition might be that the rubber banding will suddenly make that car competitive and it'll try coming back at you. Which is absurd in itself.
