With you both on there it will be lower but probably not as low as his depending on when he bought the car,changes in interest rates,changes income to debt ratio.
I've bookmarked this site to go back to next time I need a loan...
http://www.knowledged.info/go.php?link=a…
Good Luck.
Financed cars is more expensive to insurance cause it requires full coverage. You can compare how much you would pay for full coverage of this car using this tool - carquotes.sinfree.net
That depends on what the lender offers you. Most likely, you won't get the lowest interest rate possible.
I doubt that you'll get 7.5%, but you shouldn't get 12% either.