Can't purchase any more cars

[Maxim Moskvin]

The gist of it is, when I visit the junkyard car dealer with a working fuel cell controller and more than enough caps, the only option I have is "I have another fuel cell for you".
After choosing that option, he immediately takes my caps, the cell, and gives me another cockroach, the first car I bought in the game.
I even took 500k caps as a test, because the wiki says the prices are always changing and still he just takes the caps and the cell and gives me a cockroach.

[Kilgore]

You need to ask him about something special, then buy one of other cars.

[Maxim Moskvin]

You need to ask him about something special, then buy one of other cars.

I did select that but it automatically selected a cockroach. May have done a rapid double click, not sure. Gonna do a re-try.

[Maxim Moskvin]

Ok when I talk to him I get these options. If I select option 1, he immediately takes the fuel cell off me.
If I select option 2, he just asks for the key to the car if I take it there, if he not he asks me to bring it with me so I can sell it.
If I select the "any other services" he asks me about repair work or something.
And, obviously if I select 4, I leave.

Tried dropping the fuel cell to see if I could ask him what he does/if he sells cars etc. again But it just removed the option to give him the cell.

[Kilgore]

After choosing option 1:

[Maxim Moskvin]

That's the option I had chosen for my first car (cockroach)
For the last three times he just took the money and fuel cell immediately without any other option being presented to me, but I tried it again and it's working.
Thanks for the help.