sorry Doug but I plead complete ignorance on what a "goathead" is (shall google right after this) I presume its a thorn or something?
as for your commuter pain in the keester, when multiple flats happen, once I check to see that its not something stuck in the tire or a tube issue, thats usually my signal to get a new tire. Its not like I have to do this often, but for me its just worth getting a new tire when it starts getting iffy tread depth wise, and flats more often. (im careful with my money, but prefer that to the inconvienence of a flat if I need to be somewhere at a certain time and would rather not mess around with a flat)
5 in a week....thats something.