Adjustments to height, change springs, or can I leave it stock? The online rim shop says its fine but I dont trust them. Help me out guys.

Dzieki

 

you should be fine. remember, the g also comes with 18 and 19's. but, the added weight [if they are heavier] will end up slowing the car down. going much larger, lets say 20's, it may be beneficial to invest in larger brakes to help slow down the extra mass you have added to the car.

 

Actually LMGT4's are very light, lighter than the stock, but yeah so just put them on? Obviously you would have to change the height when going 19" but for 18''?

Common guys 2000$ are at stake here

 

you dont have to do anything, just throw them on. when you go very large, the height will increase and the car will look stupid, but 1" wont do much since you will lower the profile of the tire to compensate. post pics when you get them!