I know that the S5 lights can be installed on an S4, but can it be done vice versa? The reason is because one of mine got smashed and I don't have the cash for some S5 ones, too damn expensive...

I have an S4 in the garage which is out of commission for a couple of months so I can just borrow the lights until I can afford new S5 ones. Thanks.

 

Yup, they work. I installed S4 TII taillights on my S5 Vert. Looked horrible, but the worked.

 

Yea, when I bought my car, I had S4 tails on mine, and didn't even know. I thought everyone were buying aftermarket S5 tails, until someone told me that the S5 came with the round lights. So now, i'm looking to replace the S4 lights.