Well, that does make our lives a little easier.
If we go with a vehicule ambush, there are a few things we need to keep in mind and figure out.
Since this is, for all intent and purposes, a kidnapping, we need to "damage" our target as little as possible. After all, Kenichi isn't much good to us if he's dead. This means we cannot his his vehicule with overwhelming firepower, because we might kill him. And so, in my opinion, we've already crossed out everything that is heavy weapons or explosives (which, after all, doesn't matter much since we don't have any!).
We we'll have to do is either immobilize or disable Kenichi's vehicule.
So, let us look at those two options.
To immobilize; we either need to box in the vehicule with our own, or to prevent it from moving by magical means.
To disable; we either need to take the driver out, or to mechanically disable the vehicule.
A few things we should "assume" (most of my assumptions are based on the fact that our target is a professional Johnson):
-The car will be armored to a certain extent.
-The driver will be a trained professional.
-The car will have an alternate source of power (other than Seattle's grid)
-The car will be running on Run-flat tires.
To my knowledge, the heaviest firearm we have at our disposition is Jack's AK98, (@JACK: What ammo do you have for the AK?) which might be able to punch through armored glass, and take out whoever is driving. I mean no offense to Jack, but I doubt he could disable the car by getting a round through the engine
Thats the sort of stuff Delta Force snipers do, not bodyguards
BUT, if Jack feels confident enough it is a shot he might be able to make, that would give us a great way of stopping the car.
Vehicule wise, we currently have at our disposal the van we just acquired, and Conall's racing bike. This, I believe, is enough to rule out the possibility of simply immobilizing the target's vehicule. We might be able to borrow again the gangers van, but I personally feel it would stand out WAY too much in the area we'll hit our target.
Considering we won't able able to use our target's car to spirit him away, we have to take for granted that Kenichi will be taken in our van. This means we cannot run the risk of having our van disable, by lets say ramming the target's vehicule.
So, beside shooting the driver, the engine, or maybe the tires, we can also disable the vehicule magically; either with spells or with spirits.
Going with spirits we can:
-Have a spirit use the Accident power to make the vehicule crash
-Have a spirit use the Confusion power on the driver to have him crash
-Have a spirit use the Binding power to prevent the vehicule from moving
-Have a spirit physically manifest INSIDE the car
-Have a spirit manifest outside the car and physically "attack" it (ex: an Earth Spirit knocking the car on its side)
Going with spells we can (and here, I speak for Conall):
-Use a Powerball to cripple the car
-Use a Shatter spell to cripple the car (which, honestly, is sort of insane because its a touch range spell, but it WOULD be awesome to have Conall just "tackle" a car off the road
)
As to the efficiency of said spells, simply take under account that Conall can cast the Shatter spell and easily deal out as much damage as a AV Rocket if needs be. Same goes for the Powerball... but since its an area spell, the drain's a bitch, and a high force Powerball WILL damage the surrounding area a great deal.
In my opinion, we should plan on using two methods. If one fail, then, we can rely on the other. For exemple: if we have Jack try to shoot the driver, and he misses, well, we can then Powerball the crap out of it
As for what I would pick: have a powerful spirit use the Accident power.
BUT, if by some miracle the car isn't really armored, and Jack believes he can "snipe out" the driver, I would say:
-We block the target's car at a light (either with the van, or by having Conall "fake" an accident between his bike and the target's car)
-Jack takes the driver out, and then is in position to cover Conall.
-We have one, or many, spirits manifest inside the car to subdue/kill whatever security detail Kenichi has.
-We take the target out of the car, bag him, and put him in the van.
-We get the hell out of Dodge.