Do you perhaps mean Mr Gumpy's Outing by John Burningham? His list of works include Mr Gumpy's Outing and Mr Gumpy's Motor Car. Burningham has written and illustrated books for over 45 years, but in that time, I find no work called Mr Gumpy's Outstanding. Living in England, he has earned a Kate Greenaway Medal and an ALA Notable Children's Book award. For Mr Gumpy's Outing, he won the Boston Globe-Horn Book Award.
A very simple story, Mr Gumpy's Outing can be summed up in a few words. Mr Gumpy is a pleasant tempered man who knows how to end an adventure properly. He also knows how to start an adventure properly. One day he has a hankering for an outing down the river in a boat. Two children and his animal friends all ask to go along with him:
Mr Gumpy decides to take a trip along the river in his boat, but the children, the rabbit, the cat, the pig, and lots more friends ask to join him.
The outing goes along happily until the animals and children start to do just what Mr Gumpy asked them not to do: they start wiggling and squiggling:
Everyone's having a lovely time until the animals start flapping, hopping, bleating, and kicking ....
Now--the outing is going along swimmingly because everyone is in the river swimming to safety. All ends well when Mr Gumpy has everyone--now safe on land--gather round for a nice warm tea in his nice warm home.