...could he perhaps see the process of entering this construct demonstrated first.

Caiden doesn't understand Blai's objection but fortunately his usual method of dealing with this kind of problem is to get in himself to demonstrate that it isn't scary or boobytrapped or full of monsters or anything.

So you sort of - duck while sitting - and you don't have to tuck in your legs particularly fast because the hatch doesn't close by itself, good. He will sit.

He gets in the construct himself. Soon it is going terrifyingly fast down the street while playing something that is probably intended to be music! Caiden is singing along, at least.

Blai is going to throw up on his own knees.

Understandable. Caiden hands him a barf bag from the glove compartment. 

Is this - supposed to mop up the vomit - it doesn't really seem suited to that -

Okay, sure, Caiden can try to one-handed mime vomiting into a barf bag without taking his eyes from the road.

He doesn't have any more vomit but the belated gesture is appreciated.

This retroactively makes Caiden's decision to take Blai to a Chipotle seem... not the best. 

Anyway. 

Caiden can clean up the vomit, and then they can go inside. 

Blai has flatly no idea what to do with the Chipotle. He will stand where Caiden seems to want him to stand and look at things in blank incomprehension. He is pretty sure based on the smell that there is food here and that's all he's got.

Caiden points to a food and orders it, and then it is put in a bowl. Then he looks expectantly at Blai. 

Is he... supposed to point at a food. He just puked, there's no point throwing good food after bad right away. (Well, he's probably not food-poisoned, he Created all the food that constituted his breakfast himself last night and that's good for twenty-four hours, but he's clearly got something.) ...he can't explain that and there's something in the Acts that he can't look up right now about food being important and especially for sharing food to matter to things. Maybe that's what this paladin is doing. He will point at some food.

Then they will receive bowls of food to eat! And also strange transparent containers of water. 

To Blai's eye, Caiden doesn't seem to pay for them, although he does do something strange with a plastic card.

(Chipotle doesn't serve alcohol. This is important, because if he had alcohol he would drink, and if he drank he couldn't drive, and he doesn't want to expose Blai to Ubers or some poor Uber driver to Possibly Confusing Nyarlathotep.) 

They have so many half-invisible things. He doesn't even know what this material is, actually, maybe it's naturally half-invisible like glass. But it's very considerate to provide water while he's been asked not to cast spells! He eats his bowl of food.

This... is kind of boring, actually, and if he is bored then he has to think about The Horrors. 

He takes out his phone and starts scrolling through his carefully curated set of discourse-free Reddits. 

Blai does not recognize the magic item but it's not very interesting to watch from the back.

He shows Select a particularly cute image of a kitten falling into a box.

...there is probably something meaningful about this tiny illusion of a falling cat or why bother, but Blai cannot for the life of him figure it out.

If You're Bored, They're Bored. Show Them A Picture Of An Interesting Fish. 

How confused does Blai have to look before this man will acknowledge that showing him pictures of animals does not succeed in communicating anything?

He can look at the back of the phone instead! Caiden won't stop him!

Or he could just finish his bowl of food! But he's not sure it really does the rapport and bonding and and common cause thing Iomedae was talking about if also during the entire meal someone is showing you mysterious animal pictures so sadly this will be a somewhat wasted bowl of food.

Not that wasted, they need something to do while someone gathers the interpreters. 

The meal finishes. Back in the car. Most of downtown Boston is protected by an Eye of Light and Darkness, which doesn't allow in Outer Gods or their servants and causes great pain to those aligned with them. Does Select appear to react as they cross the threshold?