It really all started with hours of careful planning to get our bodies from Lagos, Portugal to Sevilla with the goal of NOT spending a ridiculous amount of money on transportation, and NOT spending 12 hours of our precious vay-cay time making what should be a 3 hour trip. Let me first lay down some rudimentary knowledge on you, so if you should ever decide to make a similar trip (and oh for sweet baby jesus you should), there won't be any pacts made.
You might be thinking: "Molly, get a freaking rental car, and call it a day!" Wrong-o, boy-o! You will quickly find that taxes and fees for international rental car drop-offs are astronomically high (even between E.U. countries). In the spring of '08 (this year) it was going to be over $1,000 TOTAL for a four day rental of a four-door manual compact (www.arguscarhire.com actually had the best prices I could fine for Portugal). Don't be fooled by initial costs, they will stick-it to you just as you are getting super psyched that everything is going to work out.