Tilly, my 7 month old tri color Pembroke, is a great dog.  She has not destroyed anything, not shoes, or electrical cables, chair legs or anything.  She is the best puppy yet.  She's had several problems that needed serious training to rid the behaviour.  Done.  Success.  But there are two remaining behaviours that my training doesn't seem to be working for.  The first one is: getting all worked up and wanting to chase cars.  Not a healthy past time for sure.  I have spent a good 6 weeks walking in the neighbourhood treat training and everytime I would hear a car coming I would say, "watch me" and as the car passed I would give a tiny yummy piece of hotdog. Another technique was to say as I tossed several treats on the ground I'd say "find it".  That works well too. BUT, as soon as I'm not paying attention, or don't treat her, she's right back to turning in circles and yanking the leash and barking like a crazy girl, to get at the cars.  I don't know if she's afraid, or she just loves the thrill of the chase being a herding dog.  I think it's very instinctual and I'm not sure what to do about this.  A shock collar perhaps?  

The second problem is her habit of digging in our backyard.  The neighbour lady 3 doors down feeds the squirrels and the blue jays peanuts in the shell, and hazelnuts/filberts in the shell.  The squirrels bury them in our lawn.  This is partly the problem, but sometimes she just gets chewing on grass shoots and one thing leads to another and uh oh, I dug another hole!  She gets out for off leash walks/runs for 1 1/2 hours or more every day, or sometimes I go twice a day as she really needs lots of exercise.  I also play with her and she wrestles with my Golden Retriever a lot as well.  As soon as she digs a hole, I put her stools in it and then fill it with tiny twigs and some of the dirt, so that the hole doesn't get bigger.  At present we have 10 holes.  Does anyone have any suggestions?