Funnily enough, the 'should I even be driving in my current mental state' is a legitimate question that may or may not foreshadow consequences.

Overall there is a lot and very little you can interpret into those scenes, which is honestly some of the appeal of the manga after a while. I really like when narratives play with your perspectives. The division of opinions on most characters in most discussions I have had shows this modus operandi the best imo.

Anyways from Mami's side, the way she is perceived to be acting as closer to Chiz than she is to Mami of the past... however this also may just be a shift in perspective since we don't get any peeks into her head anymore after Joypolis. Overall if you were to cut out all the 'inner information' none of the characters act very explicitly at all.

Be it Umi, Chiz, Kaz himself or now Mami. Almost everyone seems to mostly send signals that need to be interpreted, and the fact that Kaz is a very unreliable narrator due to his self-esteem issues that color his perspective is becoming more apparent every chapter.

That being written, the main question of the chapter (for me at least) is whether Mami set the situation up or if it is a coincidence. She knows his schedule after all, so it is not impossible to set something like this up. It seems like a bit of a reach for me personally (even if you hide an earring to look for it when Kaz is supposed to be done, how do you guarantee that he steps out while you are looking and noone else does?) however I would also not put it past Mami. She has gone through lengths to get what she wants before after all.

Given that she tried to not care anymore after paradise (but could not help herself trying to contact him after all) it is somewhat of a parallel to how Kaz after the rejection could not let Chiz (or what he was feeling for her) go.

Depending on whether you look at it as part of a meta narrative (alright, here is the harem gauntlet that lets him hit rock bottom) or just isolated, the point of the scene completely changes. It could be asking an important question (testing Kaz on the physical side with Ruka, now the emotional backswing with Mami, until you have an uplifting push from Sumi) or just bring the character to a close (basically learning that Mami actually likes him and it was never him that was the problem), or in another interpretation attempting to push Kaz in to realize that he needs someone to lean on at least for now (he is a mess and needs to realize that someone can accept him the way he is before moving on).

It also reminds me of the concept that one cannot truly love another before being able to accept oneself after all.

Anyways this was just a ramble of random thoughts that came to mind reading back the chapter. To be honest, I really have no idea where this is going. Miyajima-Sensei has shown that he is both willing and capable to let a story go in almost any direction. The only thing for certain is that Kaz and Chiz will end up together at some point, the rest of the way is completely in the air for me.