I bought this rather hesitantly, as I've read bad things about cassette to ipod adaptors. It was only £10 so I thought why not. I'm really glad I did. Rather than buy and install a CD player for £90, I've spent £10 and have my whole Ipod library whilst driving.
My tape player is vertical, so don't know if it would work in a horizontal one.
I drive a Ford Fiesta X Reg, and it works brilliantly in this car. Sound quality is fine, only the pickiest of people will complain. No tape noise or anything.