The Model S divides between front and rear what is solely in the front of the Bolt.

 

Here's a photo of the drivetrain of the RWD version:

Still looks much simpler than the Bolt (no mess of wires and whatnot). I'm actually surprised just how simplistic it looks.

 

I think the "mess" to match the components seen in the Bolt has not yet been added.

 

Ok, I stand corrected. Here's a photo of the front end of an AWD Model S that was being repaired....lots of spaghetti noodles in there:

 

I see a few things that aren't shown on the Model S diagram
1) A LOT of cooling
2) Brake controls ABS and fluids
3) A Big honkin power inverter
4) A charger
5) HVAC equipment
6) Control modules (computers and so forth)

Now I don't know enough about the Tesla to know if some (or all) of those things are have been omitted from that Tesla diagram or if they just don't exist on the Tesla, or if they've just been incorporated more elegantly in the "skateboard".

[EDIT: Bro1999 and others beat me to the post]

 

Yet they still found space to allow for the FRUNK large enough for a spare tire if wanted.

 

Yeah, but the tesla is huge compared to the bolt EV. Add 4 feet to the front of the bolt and you can have a huge frunk

 

One of my favourite ads is the one that Dustin Hoffman did years ago for the VW Fastback Sedan.

(Opens front lid) "It's got a trunk up front where most cars have their motor."

(Walks around to the back of the car) "And in the back, where most cars have their trunks, we have a..."

(Opens the trunk and looks inside, does a double take) " (heh) it's a - a trunk. A... a large trunk".

 

Initially I was also surprised how tall the stuff in the engine compartment looks. It appears as busy as the Volt, while the Volt has an extra electrical motor and an entire ICE as well. I think the designers deliberately gave up on the frunk to reduce the size of the nose and the entire engine compartment.

Here is why. Consider the Volt. An ICE is tall, running ~2 feet from the overhead camshaft down to the oil pan. Therefore the engine block needs to be placed in front of the front wheel axle, together with the transmission and its 2 electric motors. That pushed the Volt's front wheels back into the cabin. Its also the reason why Volt-1 and Volt2 have so much more front overhang that the cool looking Volt concept car:

Instead, Volt looks like this with a lot of front overhang:

The Bolt feeds the front drive axle right though the motor and the transmission. So the electrical motor is in line with the front axle. The Bolt also has no tall in-line ICE to store, so there is a lot more flexibility.

Therefore it was possible to pull the front wheels forward towards the bumper, creating a longer wheelbase and more cabin space. The only thing in front is the coolant radiator which in the Bolt doesn't need to be that big anyway. the result is a car with very little front overhang:

The BMWi3 does the same trick of a short nose, but because it is rear-wheel driven does have room for a frunk. But the i3's frunk is so tiny that its hardly worth the trouble. Bolt stacks all machinery in the front, I understand why it doesn't have a frunk.