Here's all the contact info I have:
Whitehouse: (202) 456-1414 - Fax: (202) 456-2461
Address:
President George W. Bush
The White House
1600 Pennsylvania Avenue NW
Washington, DC 20500
Don't be afraid - be mildly assertive with the switchboard saying how your Dad's idea could save us a lot of grief and economic losses with little damage to the environment given the low emissions of modern cars. Of course the EO would be temporary - just til things get back to normal.
At least ask that a message be passed towards President Bush. Don't let them pass you to the EPA. ;-) Good Luck!
Follow that with a second order to commence drilling in Alaska!