That's the problem... everyone focuses on polygons as if thats the only thing that will change...
GT4 cars were super high poly counts for the time (photo mode models especially) but guess what? No interiors modeled... that right there killed any kind of future proofing.
So the assumption that GT5's high poly cars make them future proof is flawed again becasue it focuses on just that one factor... what if the future allows for things like advanced damage model of an actual chasis and includes thickness and strengths of different materials? GT5 cars have none of that recorded.
What if advanced features like modeling actual weight distribution based on every part is used? What if damage actually skews weight in real time? GT5 cars do not have every part weighed, just overall car weight with possibly some overall weight distribution info.
How about undercarage wind resistance based on actual part shape? Not just cars that have a flat textured bottom...
And the assumption it would take so long to model is also just a guess... PD seems to do things the really hard way which takes a LONG time... but laser scanning has come along and who knows what techniques are coming down the pipes for the future? Plus pretty much every new car has really detailed computer modeled version from the factory already... that would save you a LOT of work.
See there is a reason almost nothing is ever future proof... you can't account for what might get invented in the future.
Graphics cards are never future proof no matter how fast the GPU because a new shader comes along or physix is the next big thing.
RAM is never future proof no matter how fast because a new architecture comes out... remember when DDR first came along?
4Ghz P4 processor? Oh look dual core...
8 USB ports, 2 Esata and 6 SATA ports? That's nice, does it have USB3?
Future proof is always a joke. GT5 cars are no more future proof because of their poly count than GT4 cars were.
Obviously future proofing is a very tricky thing these days, but seriously, some of these things you mention will never matter to video game simulation.
For a videogame developer to get into specific car specs such as material thickness, mass and density for each part for EACH car, which could have 1.000.001 different variations of impact angles, is really beyond the scope of possibility. I not even sure the automotive industry has come that far when designing and modeling vehicle safety and airbag features, and believe me the big companies do eveything to perfect engineering through computer models before going ahead with their prototype manufacturing.
As far as having the weights of individual components to replicate weight distrubution/ weight shifting, again, with so many parts it's something no videogame developer needs to bother with. However, I'm certain PD has done alot of homework in this department, and have very closly simulated the weight of motors/tranny and the chassis within their models to match real world counterparts close enough. If you think about it's already a big chunk of the physics engine, and having individual component weight is irrelivant, when all that matters is simulating the points at which the mass lies within the car model, which I'm sure they have meticoulasly worked on since at least GT3.
They could possibly work on having undercarage aerodynamics, but I'm not so sure it would help much for gameplay. I'm also not sure that manufacturers would just give up their computer models for PD to use, and the question is would PD even be able to make those work for their PS3 modeling system. I don't know, I have no clue about modeling software, but I'm sure it's not all so simple.
I'm relatively sure though as far as their premium car modeling goes, they are future proofed for at least the PS4. They're not gonna toss all that hard work in the garbage and start with a new direction of car modeling. PD is already looking to the future, and they must have some inside information on the specs that will be available for PS4. We're not moving away from 1080p resolution anytime soon, so there shouldn't be any major affordable technology shockers in the next 5 years at least.
I agree with you on the laser scanning technology though, especially when it comes to scanning the RL tracks, this would truly be the last major piece in making the game that much more true to life.
It's really easy to assume that PD could do things better and easier, but the amount of trial and error that has gone on at PD to get things right, is likely the highest out of any other game developer out there. I love how they strive for perfection, even though the GT community always finds things to pick at. Good things take time and amazing things come from many lessons learned, I think PD is on the right path.