Google has changed the way one has to search
for items like Barth motorhomes on sites like craigslist
from a multi-pronged state search
to an individual city type of a search
...so if you don't know where the items are
then one has to search city by city

...so much for life in 2016

Try this: In Google put the search term like Barth radiator and append craigslist, then hit search. It returns all barth radiators on all craigslists. At least it did just now on my Ipad. So it looks like "Barth radiator craigslist".

You can use this too

http://www.searchcraigslist.org/

search everywhere

For searchcraigslist.org, I've found that choosing sort by "Date" rather than the default "Relevance" gives better results and fewer "This posting has been deleted by its author" messages.

You can also use logical operators to help get rid of stuff from Barth, FL and the Barth used car lot in Cumberland, MD.

After experimenting a bit, I've found that this is a good search:

barth (rv | motorhome)

the "|" means "or"

Quinn