Hello, we are spending three weeks in the republic this September. We will spend one night on Inishmore at the Man of Aran. I'm so excited about that! Anyway, we will leave our rental car in the parking lot at the Rossaveel dock overnight. I think we will have a car trunk. It seems to make sense to leave most of our stuff locked in the trunk and only take backpacks to the island. Is that a good plan or do you have other suggestions? Thank you in advance. I always get my best specific info on these forums no matter where we are traveling in Europe.
Parking lots tend to attract theft so I would make sure you don't leave anything important in the car. If you leave some clothing and they take that it would be unfortunate but your trip would continue. Don't leave anything more important than that in your car. Otherwise you could take it all fairly easily and just use a taxi to get you to your hotel if it isn't near the ferry terminal.
I don't know what the security is like at the Rossaveel lot, but I would agree to bring anything of value with you. Also, try to park under a light if at all possible.