As for my SCX Frankenstein project I decided on the following:

I'll "Frankenstein" the wood track together with the plastic. I'll router the wood for the slots of course but I am also going to router a sideways slot for the arrow shaped track connectors to slide into and then screw those down and solder to my electrical connectors on the plastic track.

Picture this in your mind to visualize what I am doing: I'll cut "a "biscuit" like slot below the track surface for the connectors. Woodworkers will know what I'm describing here. A regular biscuit cutter wont't work here but the idea is the same. The thicker MDF allows for that.

The head of tech support for SCX (Bryan Young) has been awesome in explaining the electrical system the company used for their digital system. I'll explain it here and on my website at: www.mikes132models.info under the "MyTrack" page.

Okay, standard slot tracks have a two wire set up for the cars. SCX throws a "third" wire in for accessories like it's chip in the car and crossover tracks etc. This serves multiple purposes but here are the important ones.: The cars won't lose power on the track because you added accessories. They maintain the same voltage from the two wire set up. The other accessories get the third wire power to operate independently of the cars. This includes the pits stop, chronograph, lap counter and anything elseyou put on the layout that SCX sells.

The third wire is inside one one the tracks. It is MOST IMPORTANT, that you do not wire the third wire backwards or into the opposite track or you will fry (burn up) your controller system. Think " POOF " here. Cars and controllers are toast!

Under the track is a flat S-shaped piece of copper. You can remove the plastic clip to expose it and it will provide a better view of the connection inside the track.

Click on each picture to see the details.

It is worth cutting open a piece of track to see how it is made and to see the connections inside. The controller is a hundred dollars and the straight is $10.00. Learning is going to cost you money no matter how you go about it. Why not go the cheap way, right?

So once you figure out the wires inside the track, then all you have to do is create jumper wires to the areas that are wood and the same to transition back to plastic on the other end.

I'm going to use copper foil tape (from stain-glass suppliers) to act as my conductors and run the third wire across to the plastic track to continue the circuit.

So why am I doing it this way?

Because I want to use all of the great accessories SCX makes yet I want a multi-level track with long straights at an affordable investment. The only multi-level part SCX sells is the bridge for $109.00 so I'm stuck with a flat track.

Some experimentation has shown that, unlike other slot car manufacturers tracks, SCX made their track from a vinyl plastic material. It is very flexible and I found I can bend, lift, twist and tilt it much more than the hard plastic tracks I've owned in the past. If the experimentation works, I may forego the wood and expand on the flexibility of the vinyl. Watch my site for details.

FYI:
I'm building a 170 plus foot track. That's why I'm trying to find a cheaper alternative to buying track from the manufacturer. I'll need roughly 75 to 90 packages of track. At $25.00 a pack USD, that's about $2000.00 for track and shipping alone!  I'd rather use the money for cars, power supplies etc. 

MDF costs about 25.00 to 30.00 for a 4 x 8 sheet. Straight track can all be cut from two sheets. I can get about 64 feet of straight track for 50 to 60 dollars!