I don't think a pop up tent would be terribly reliable - I think after some amount of use they probably wouldn't pop very well. And all I can think about is the frustration I've had with some windshield shades that supposedly fold down easily! I would also be curious how likely they are to become a kite in the process of popping up... hmmm, where is that youtube video of tents flying around?

If you do try the pop up tents you'll have to come back and give us a review of how they worked for you.

Not sure what you mean by "reliable" - perhaps you could be more specific in what you're looking for? Maybe you mean durable or rainproof?