Check your state's BMV/DMV. Some states offer free bill of sale forms that conform to the requirements for that state.
This is the sanest way.
But you can write your own simple sales contract if you really want.
"Party A (name, drivers license number) sells Item X (VIN) to Party B (name, drivers license number) in exchange for _____ (include dollar figure) on date (date of transaction, location)." That establishes who is buying what from whom for what amount on what date and where (the latter is important for jurisdiction).
Including the phrase "All laws governing private party automobile transactions in the state of ______ are applicable" shows that both parties agree to the state's regulations. The big one in my state relates to smog compliance.
At least in my state, the title needs to be free and clear to indicate that the seller doesn't have any outstanding obligations (like registration fee payments). All of this is covered in the state's vehicle code so saying "both parties are following state regulations" eliminate the necessity to regurgitate all of the individual points.
If you want, you can throw in a line like "the sale is final and non-refundable" if that is the case. Once the buyer signs, it is clear that he/she accepted this particular term.
Do not rely on Pages to provide templates for legal documents. They vary by juridiction.