There is big weak point on this car. It is where the front shocktower mounts to the diffcasing.
In a hard enough hit or after enough hits, the wheels will shift the arms and everything attached to it and destroy where the shock tower mounts to the diffcasing. Basically, you'll have no useable front suspension. If you search on eBay, look for something called "The Fix."
The "Fix" ties in the tower and diffcasing and keeps the upper and lower half from shiftting seperately of each other. The rear is also vaulnerable BUT the front is where the majority of your hits will occur. IF you had the ver1 NTC3, you could put the fix on both the front and rear. With the Ver2, on the front can have this application.
Search on eBay for "The Fix" and the seller should be fly0 and based out of Florida.
And I wouldn't put metal spurs in it either. You want the spur to strip if it's necessary to save the rest of the drive line. This is a shaft driven car and there needs to be some give. Otherwise more damage will occur. Other than that, radio interference will be your best friend. I don't think I've ever seen a metal spur for the NTC3, but I may be wrong.