We're trading cars and moving, help?!

Hello, so I am trading my 2004 pontiac grand prix for my relatives 2007 ford fusion. The problem is that I'm moving to Arizona (I currently live in Wisconsin) in February, but my Tags are due this week which costs $75 to renew. But since I'm trading my car with my relative for her car, I don't know what to do to save us time and money. What is the legal process? Should I switch license plates and tags? If I renew my tag in Wisconsin, does that mean I won't have to in Arizona? I'm trying to avoid having to register the new car I'm going to get twice while also not knowing what to do about my pontiac's renewal? I've tried to do some research on the DMV website, but there just isn't much there for the situation I'm in. Please, if anyone knows anything, I would greatly appreciate any help. Thank you!

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