two great finds?

Recently i have been looking at local dealerships for some used cars, maybe hoping to upgrade to the GT, but nothing serious yet. And my gf is also looking for a new car and she wants a stang relaly bad ( i rubbed off on her). But this is what i have found:
Red 99 GT 5-speed, pretty basic, but only 17,896 miles all original (doesnt have factory wheels, its got some 16s but i would upgrade anyway). priced at 15 originally, but down to 13, i'm guessing i could get it for about 11500.

the other one that seems too good to be true is a black 00 auto with (i heard, no visual proof for me) only 50K miles. its basic also but for only 6700? it was like 9000 to begin with then 8500, and now 6700 cuz the guy said he needs to move it? been on the lot for 3 months, i'm thinking i need to go relaly look at it to see what its all about, but the outside is near perfect. Dont know all the details on this car, but i need to find out for that price.

also, i figure i could get 8000-8500 for mine, making a pretty small loan for the difference for the GT. ANyone know a rough estimate on insurance difference for an 48 yr old male(my dad's name is on the stang)? i know different comp. make a ton a difference, but i'm just looking for a ball park number.

that is exactly why i will avoid trade in at all costs. My gf was with my when i found the GT and she practuaclly singed a contract to buy mine for 8500 on the spot. so if i could get it for 10, i think i would jump on it.

as far as in surance situation, i'm on my dads 98 F-150, so nothign would change there, and his record is squeaky clean, no tickets of any kind for like 20 somethign years, and i dont even know of any claims, at least in the past 5-7 years for sure. I'm going to have to look into this a lot more, but there is a pretty comlicated problem with it all. my current stang was a b-day and x-mas gift ( for like 3 years, litteraly), so pops is paying the loan for that, i would have to pay for loan difference and insurance costs of course.