Text join unique and filter

I have created an example of the data I am working with (below).

TEXTJOIN(" / ",1,UNIQUE(FILTER(A:A,B:B="CAR")))

This gives me A / B / C. 

But group A CAR didn't make any after YR 1.

I am attempting to list all unique groups for a certain criteria if the group has a cumulative value over 0 from year 2 and out.

With the expected outcome to be B / C