She manages to slip out of every harness we've had for her. They're the ones that the neck and the front two paws go through - kind of underpants shaped when off. I've even altered one to make sure it fits properly as she has a slim long neck and a barrel body. I've looked at the 'webmaster' ones (think they're called) - they go across the whole body, but I'm not willing to shell out up to 70 quid on one. What other options for my wriggly terrier girl?