I know this is almost done and dusted, but it was mentioned on another thread, so I thought i'd throw a few options into the above slogans  
 
   
   
 
I'd be unstoppable - if not for law enforcement, physics and 
Wattie !
The police never think its as funny as 
Wattie does
A clean house is a sign of 
Wattie's out riding 
With great horsepower comes.... 
Wattie
If you can read this, you're coming second behind 
Wattie
Will wheelie for boobies and 
Wattie
It's important to know your limits, cause 
Wattie has none
To ride or not to ride? There is no question, 
Wattie is the answer.
If you're not on the edge, you're taking up 
Watties space.
Wattie is living. Everyone else is just passing time
Wattie rides way too fast to worry about cholesterol
Because Golf is stupid and the shoes don't suit 
Wattie
Head down, Arse up, Knee out, try and catch 
Wattie
Never trade the thrills of 
Wattie for the security of existence.
Sometimes it takes a whole tankfull of fuel before you can think like 
Wattie
Life is too short to sit in traffic with 
Wattie
When in doubt power out like 
Wattie does
Do not attempt this at home, 
Wattie is a professional
Wait 'til you see God, then 
Wattie, then brake
It's only illegal if 
Wattie gets caught