I currently have +40mm offset all around. And i was wondering what the appropriate sized spacers i would need to make my car look flush.

I'd like to see the wheels sticking out when looking head on at the car like this:

Picture of my car

 

You can put some 25mm spacers in those wheels if u gunna get another wheels u can get some 9.5s with +30 +35s and you won't have any problem imo

 

depends on your ride height.

 

its on stock suspension

 

Search. If it's worth asking about then it's worth searching. The topic has been discussed to death and unless you want your stance to look like **** then I suggest you put forth some effort to try and understand the topic of wheel fitment and suspension.

 

If your gonna lower it, just make sure you don't lower it too much, or else you need to bend those fenders.

 

First off...how wide are the wheels?

Offset by itself is useless..it is a relationship to the hub face and the wheel mounting surface

You need to know how wide the wheel is to tell where the outer edge of the rim will end up

 

Check this before u get flamed real good ;-)

https://www.rx8club.com/series-i-wheels-tires-brakes-suspension-55/

 

^^^^^Take a look at the second sticky in the list.

And like dannobre said, you need to take into account the wheel width in addition to the offset to determine the position of the outside wheel face.

"Flush" also means different things to different people. Generally speaking, 25-30 mm farther outboard than stock is flush. This means a +20 to +25 offset on the stock wheel (8 inches wide).

Also, as others mentioned, ride height needs to be considered as well as camber.