You mean do the cars smash up when you crash?
Yes they do smash up,the detail is incredible,the cars smash up better than any racing game. You can even leave smash/crack marks on walls and buildings,your character can even smash and fly through the windscreen.
The damage in GTAIV is very good.
Mac or PC?
cars in san Andreas have infinite gas, so they never leave you in the middle of a dessert witout gas. Cars can explode though if you crash it too much.
You cannot, GTA SA has a much lower graphic system then GTA IV, plus the cars in GTA IV have more addons than GTA SA.
All of GTA cars that have been made are just GTA cars. There isn't any real life cars, unless you MOD them.
by modding them
you can't
Taxis
no it does'nt
No
no
nowhere.
There are no trademarked cars in GTA. There are some that might look like a Honda, but no Hondas.