$53/mo for full coverage on a Corvette for a 21 year old? Were you blowing your insurance agent?
This is in response to everyone's comments, but you were the first so I quoted yours...
Yes, $53/month for full coverage when I was 21 (still the same price and I'm 23 now). My rates dropped in HALF when I got off of my parents' policy. The WS6 I had was $80/month on my dad's policy. When I went on my own it dropped to $40. Believe me, I was shocked, too. Even more when I found out it was only going to be a $10 increase with the Z06.
The following reasons would be why (I assume, and from what I've been told). Perfectly clean history, multi-vehicle policy so the Vette is listed for "Pleasure Use" or whatever, and my credit score is about as high as it can be at my age (spanning 750-780 between the 3 ratings). Apparently, credit score is huge with insurance rates. I don't personally agree with it, but it helps me in this case for sure. Also, I live within 10 miles of where I work which plays a part. Lastly, it gets a multi-policy discount - originally with renter's insurance, but now with homeowner's.
Regardless, it's not a typo and that's what I actually pay. I switch coverage on vehicles every 6 months due to MN winters - so I take it off the Vette and put liability on my beater truck. Point is, they've had plenty of opportunity to catch any potential "mistake" on their part. My total monthly insurance is slightly over $100 because just liability on my Cobalt or Silverado (depending on time of year) is approximately $55/month.
Back on track to the OP - I'm not a fan of either the Mustang or Challenger, but I'd go for the Challenger.