What am I?

I start with S and end with IT, and have you in the middle. What am I?

related riddles

I live in my little house all alone. There are no windows or doors, and if I want to go out I have to break through the wall. What am I?

When you are inside me, you will be encouraged to slam other cars. What am I?

You buy me, but I don't have a price. What am I?