Story is a normal Earth girl is meeting her alien pen pal, who she talks to about everything. When the pen pal arrives, the girl goes with her in her flying (?) car and hears more about the alien world, which the alien says sucks.
The girl asks to go home, but before they drop her back off, the alien switches their bodies, so the Earth girl's consciousness is in the alien's body and vice versa. The alien says she knows everything about the girl, so she will be able to fool the girl's parents.
It ends with the girl in the alien's body watching the alien interact with her parents, disheartened because she once did this exact same thing to another Earth girl to escape the alien world.
I have clear memories of black and white, pencil-sketch looking illustrations to go with it. I feel like I read it in middle school, and I'm not even sure if it was a book or a magazine, or what! I know it is similar to the other alien pen pal story (and might be based on it??) but it's been driving me nuts. Tyia!