Hearing great things about any car company doesn't matter. Or hearing bad things, either.
You're not buying the company, or the cars the people were talking about. You're buying the specific one that you are looking at.
And unless people said great things about that exact one, it's totally irrelevant.
For 300$, you're buying a car that was thousands of dollars, when new.
So, consider what shape the one you're looking at is in. $300 barely buys a set of decent tires. An entire car? Total, and utter crap.
It's 300 now, but expect to spend thousands on it, in repairs, catching it up on maintenance, etc.
If you have to ask if something is a good deal...it's not.