Sounds like they stop charging storage fees after so long.
For example, $30 a day for 45 days would be $1350. If their cap is 45 days, it stops accruing after $1350.
The repo fee is often extra. Never heard one as low as $100.
Storage fee is paid to a 3rd party, but charged to you.
I have not heard of caps.
Similarly, if your car is sold at auction, the auction fees will be charged to you. And a clean up fee if the lender determines to have it cleaned and many do. The nice cars may have a full detail while cheap ones, just all junk removed & vacuumed.
A friend of mine worked for Toyota Motor Credit for years way back when so I heard lots of stories.
Back then, their minimum repo fee was around $250 I think. More for hard to find cars. I never heard of a repo processing fee but it would not surprise me.
If your storage fee is $30 a day for 18 days plus a $350
repo fee and the $100, that is at least $990 over and above however much behind you were. Plus late fees.