They are broke - affording it is the hard part. If you really want to help co-sign on financing, lend them a vehicle, offer to car-pool etc
Poor people need even more help give they have no room for error.
No. They are suggesting that one easy way you can help a broke friend out is by being there for them so they are not taken further advantage of. It in no way implies what you wrote.
This is terrible advice. If you want to give somebody a gift, give them a gift, don't enter into a contract where you share their financial obligations and give them a financial incentive to leave you on the hook.
That is: we for better or worse live in a society where a good credit score is effectively mandatory to achieve financial independence. Helping someone build that score is risky, but is also a far greater benefit than some one-off gift; if you can afford that risk, then it's very much worth considering.
I work for an auto loan lender. If you want a fair price, I recommend CarMax. They are fair. You won't get a great deal there, but you also won't get a bad deal there. It is right down the middle.