Just thought I'd share that I requested quotes from 4 different town car/limo companies. I haven't heard back from all of them yet but the company that is endoresed by Disney is called Best Limosuine.
For a sedan that would hold 2-3 people the quote from the John Wayne airport to
Disneyland is $102 (includes taxes, fees, and gratuity)
from Disneyland to the port is $128 (all inclusive)
from the port back to John Wayne is also $128.
I also priced out what it would cost from this company for a 6 passenger stretch limo.
From John Wayne to Disney = $132.29
Disney to the port = $233
Port to John Wayne = $233
Again those included all fees & gratuity.
At least it gives you something to compare. If you use a shuttle remember the cost is per person so depending on if you have a lot of people or not, might be cheaper to do the limo.