i have a pink gooby for vixie and a black gooby for dodger (the gooby and the puppia are VERY similar) they fit very nicely, and are very comfortable.
I think there also GREAT car harnesses because their wider on the chest theres alot more support/padding on the chest incase of a sudden stop.
yes tags go on the collar. no dog shoudl wear ANY harness at all times, it should only be used for walking...a collar and tags should be worn at all times incase the dog manages to get out or during an emergency.
my guys all wear their collars with tag and a bell, they wear their harnesses when we go in the car (they get clipped in) and when walking. they fit the chis nicley, but make sure you get frm somewhere you can exchange sizes if your unsure...i bought a med for my 5lb female but it was too big so returned it for a small and its perfect.