[21jt]

I'm new here but I have a 2009 CTS I just purchased 20 inch rims and I got 245 35-20 tires I'm wanting to put spacers on at least the back wheels was wondering if anybody has put spacers on a CTS they can give me size spacer I need to get the Wheels flush with the fender or as far as I can go without rubbing

 

[AAIIIC]

(1) Your punctuation keys all appear to be broken. You should get a new keyboard.
(2) Your 2009 CTS is not a 2016+ CTS-V, so posting in the 2016+ CTS-V Appearance Mods forum is the wrong spot. I will move this to the proper forum for you.
(3) "Flush with the fender" is a subjective thing; nobody can give you an answer to tell you how you want your car to look. Go outside with a tape measure and measure how far you want the wheel/tire to come out.

 

[wcthunder]

it also depends on the rims you'll be sporting. Plenty of info on our forum, we've discuss this many of times.

 

[CaddyFred]

Don't forget the longer studs you'll need with the spacers.

 

[supedeville]

I use a 5mm spacer on my 16. It's the biggest you can go and not need to swap out the bolts.

5mm does not make that much of a difference, but I needed to clear the suspension.

 

[CaddyFred]

^ I'm surprised you still have safe thread engagement with those spacers.