Thank you Kassidy, yes I've been told by others it tends to be a BC thing (as well with some other dogs just a 'doggy thing').
Hard to say as, fortunately, she's always leashed. But my guesstimate would be it's a 'hey they move, I'll chase them' thing. She does try to chase birds too and those seagulls, well they're fair game! Leaf also tried to chase all birds but now only tries, more half heartedly of late, with the seagulls no other birds when on or off the lead but she never tried to chase cars. So with Blossom, who's just discovered she's almost a teenager and is now really 'testing the boundaries' big time, I think it's more play or herd. Don't think she's protecting the house as it happens any time along our walks.
She is improving though, provided I can get treats into her mouth quickly enough, or she's more interested in sniffing the latest peemail. Plus does depend a little on the car. For example a quiet car doesn't arouse as much interest as a noisy one, or one driven over the speed limit (maybe she's thinking of becoming a Police Traffic Dog

). But strangely a very loud motor bike didn't evoke any interest. Possibly because we were on the busy road, we cannot totally avoid that as 'all roads, ways etc.' lead to it with the motor bike it was just 'another noise' and she's not afraid of loud noises etc. We have two major roads surrounding us so this is something I really have to work on and stop now!
Not helped either the other day by the two kids who live in the front unit. We'd just got to the bottom of the drive way, two cars one coming around the corner and the other coming up the road, so Ms.B, who does tend to let the world know she's off on her walk, was kicking up quite a fuss. One of the boys decided it was 'fun' to lean over his fence and go 'WOOF' 'WOOF' right in Blossom's face!!!!!!!! Whilst his darned mother stood in the door way and laughed! I did tick him off, couldn't help myself. And they wonder why kids get bitten by dogs!


I told him, politely and quietly but very firmly to not torment my dogs and how stupid it was to do so. Hope he's learned not too as this is not the first time those kids (their twins cannot tell them apart) have teased my dogs. They actually threw a hand full of road grit from the verge at Leaf's hind quarters. I didn't, unfortunately, see them do it but heard the stuff drop and of course saw Leaf 'buck' as it hit! I did turn and glare at them but seems they think tormenting dogs is funny, along with their mother


!
Sorry for the rant but I was and still am fuming, as it's the dogs who suffer from this idiotic behavior, not the kids! Don't torment my dog or any dog or animal if I'm around, because I cannot keep quiet!