How long does Restor FX last? How durable are the fillers?
It lasts life of the car but we normally would say 10 years.
Does it abrade over time?Does it scratch? Can it be buffed if scratched or one has to reapply?
It does scratch but not that easily like other cars. Normally same type swirl marks you can see on a car just 5~6 months old will take minimum 3 years to appear.
There is also guarantee that it will never flake, if it does, they will redo the whole car for free, which is a very painful process
Is it chemical resistant? Can we clay it or there is no need to clay it ever. Does it get affected by tar and iron and can we use tar solvent over it to remove tar etc. Is it prone to water spotting like coatings?
It is as resistant to chemical as much a normal clear coat of a car would be. I've yet to see a restored car with water spots. Normally water beads over the coat as if its waxed. Although there is no need but if you want or need to, you can clay just like any normal car.
http://www.restorfx.com/renew/