Well, my ME3-induced depression is finally coming to a middle, so I guess it's time to get back up on the kakliosaur and pound that grindstone.
An important Odo episode here, particularly in the way it affects his relationship with Kira. It's a good thing that the show has finally returned to Odo's struggles, he was the star of season 3, but so far in season 4 he has been in the background due to his conflict with his people being less urgent. Even in this Odo episode, there's nothing about the Changelings, it's all about Kira and how oblivious she is to his pain. In fact, this obliviousness from Kira and the lack of development for her character are problems with the episode, but I'll talk about that later. What saves this episode is a great performance from René Auberjonois, which is particularly notable considering Odo spends most of this episode as a tire.
The plot is very weak, a Cardassian terrorist organisation that never get developed properly blows up yet another runabout. How many times is Star Trek going to pull off the old tale about two people crashing on the surface of an alien world? Oh well, I suppose I can forgive that lack of imagination because of how imaginative the rest of the episode is. Kira and Odo need to make their way across a rocky desert to find rescue, so it's lucky that they crash landed next to an old 4x4. It's unlucky that the vehicle has a flat tire, but Kira finds a solution by convincing Odo to turn himself into a new tire, which she then fits to the vehicle and drives off. This is the meat of the story, watching Odo deal with the pain of being driven over pointy rocks is really emotional, and this is easily René's best work to date. You really get to understand what it must be like to be a tire, and the anger that comes from having your face pressed into the ground constantly.
Sadly, Kira's role in the story isn't as good, she drives the vehicle while listening to the radio, with the volume so loud she can't hear Odo's screams. I know that some people love it, but I think the scene where she sings along to Girls Just Want to Have Fun was gratuitous and not all that funny. The episode also has a sad ending where, upon returning to the station, a slight wedge has been driven between Kira and Odo's friendship.
Runabouts Lost: 5
Form of... a Tire: 25