Bought a used car checked it over engine wise look...

Bought a used car checked it over engine wise looked under the car etc... I was pretty thorough. $5k beater car. Wasnt expecting much but for that price I made sure to check everything out as much as possible.... Except....The salesman popped the trunk from inside the car to get a look at it. Now a week later and the keys don't even open the trunk so at some point I'm guessing a locksmith replaced a lock. So know the only way to unlock the trunk is from inside the car. The salesman also pressured us to 5 Star rate this so now after 5 months I noticed this rating and thought.... Hey I'm updating this. The gas float sometimes sticks to and the engine lights on. Called but got nowhere. Minor stuff but for 5k for 2005 it shouldn't even have these issues.