They are pretty fast on patching stuff but this one works as of 12-3-2015
What you have to do:
1. Buy a Rusty Rebel (You pay 3k for it )
2. Drive it down to LSC
3. Go down to rims > Offroad > stock > raider (You pay 5k for it)
4. Go to horn > look for sad trombone (Here is the glitch you put it on your car but you don't have to pay for it)
5. Sell the car and you made almost 40k in profit
You can keep selling the rusty rebel as there is no 45 min wait time
Exploit is not found by me and video is not made by me just sharing to ownedcore community
Edit:
If you can't buy the horn yet or don't have the horn because of different console then skip step 4 and buy the rims and sell the car you make round 20k/30k profit.
Whatever you do don't go look through the rest of the garage stuff like the chrome wheels. If you do that then you will get charged for the sad trombone. If that happens then turn off/on your console and give it another try. Should have fixed your problem.