Legal Question in Investment Law in California

Yes, but anybody who can't get a loan from the bank has bad credit. This is because they stiffed the bank -- and You're Next.

Yes, but don't co-sign on a loan made by someone else, because you may be called upon to make good on it at a time when that's not something you want to, or can, do; and avoid charging usurious interest. A discussion of the allowable rate can be found at http://ag.ca.gov/consumers/general/usury.php.

Dealers even more than banks are eager to make loans to halfway decent credit risks so they can sell more cars. As Mr. Stone suggests, your loan will be high risk.

Further, loans made by dealers and banks will be collateralized by the car itself. You could take the car as collateral, but (a) how to make a secured auto loan meeting DMV requirements is beyond the scope of this forum, and (b) so is how to do a repossession that meets the requirements of the California Motor Vehicle Sales and Finance Act (Rees-Levering Act), but you could perhaps learn this from an on-line source. Otherwise, you are probably making an unsecured loan without a right to repo the car.

It is perfectly legal, but hard to do safely in terms of really making sure you are repaid. You can use a UCC-1 filing and a DMV lien to assure payment, but only if you dot your I's and cross your T's. Not something for an amateur.