it sounds like you not socialise them enough,? at that age they should be used to people,motors,animals . you got keep taking them to busy places, go out side a pub etc ... just sit there nice calm don't keep fusing them, just chill and let people just walk past them, the more people they see the better, keep at it nice+steady make it no big deal .
spot on,i sat in asda carpark with one of mine looking like a right dodgy tit, but it worked,atb mc