I have a 1997 audi quattro 1.8t and I have 19x7.5 in rims on them, how low would i guys reccommend I drop my car?

 

From stock suspension height (not "Sport"), you can safely drop the car up to 25mm. After that, you'll need more info -like what are the tire's section width and the offset of the wheels.

 

yeah you have 7.5 wide rims so you can get a 225 tire on there (maybe even a 215 if you had too) and go lower if your offset is not to low.

and for the non-metric thinkers - 25 mm is pretty much an inch. (25.4 mm = 1 inch)

 

cool thanks for the conversion Brrman ....MM are pretty cool the make stuff sound bigger than inches lik I could say "hey my ***** is 180MMs" and people will be like wow thats big

 

HAHAHAHA just like me.... i had the same question.
Well i have 19 inch rims aswell on my 98 A4 Q 1.8T and i have had koni coil overs put on and then dumped to its full potential which is 40mm on the front and 50mm on the back!
looks awesome!!! perfect ride hieght and no worrys in rubbing. Although you may get a bit of rub on the front wheel arches but thats just the plastic and i got that fixed....

 

This needs further elaboration.

With a dropped suspension on 19's there is too much controversy; please clarify with details on what was rubbing, under what conditions, and what specifically was remedied.