There is a much easier way to do this:

1. Park journey into garage door
2. Go into garage and choose car you want to sell
3. Drive it out
4. Don't move the car, just walk back into your garage on foot
5. Take out a BMX
6. ride that out.
7. Don't pedal on the BMX, get off of it.
8. Get into your car, sell it at LSC
9. Call MMI and replace it
10. Call your mechanic to bring the car you just sold.

I just bought a new adder, because the one I had been using only gave me 120k$. I was told buying a new one and trying the same method with your own car would work better, and gve you 600-750k$

But I did your text method,damaged the car really bad, and it's only selling for $1300

Yes, $1300
I am quite sure that's the selling price of the Rebel

Anyone have advice?

Meh it involves bmx, which is just long in my opinion :/

I always get like 80k for an Adder lolol.