Protecting from Cones...
Blue Tape AKA... Modern Wedgifying your car
In Autocrossing, you eventually will hit cones. If you don't, you are missing the point of exploring the envelope of the car. There are some things to consider because of this.
Normal cones should NOT damage the fiberglass of the Elise. Anything is possible, heavy cone, hit it square on at 75mph, cold day... etc. But normally it is not a problem and I should know.
There is one area of the Elise that is an exception. The license plate plinth, that rectangle of clam that protrudes on the front. A direct cone hit on that has been known to crack the clam along the bottom. I recommend reinforcing this area on the inside.
Cone marks are to remove off a waxed painted surface. Many products will work well to remove cone marks... I like Bestine myself (concourse guys cringe!). But Goof Off... or the orange stuff, bug-n-tar remover...whatever floats your boat. Probably best to rewax the area.
However, cone marks on the 3M film suck. Really suck dead bunnies up a straw. The smudge from the cone will embed into the film and will require more heavy duty solutions. One thing to keep in mind is keeping the film well waxed also. But another trick is the application of the blue painter's tape, available from Walmart or Home Depot or any place they sell painting supplies. The only stuff I like for removing the marks on Starshield film, is MEK (Methyl Ethyl Ketone). Careful with this stuff!
The areas most likely hit are first the area directly in front of the rear tires. Mostly on the passenger side. The car is wider at the back and that will catch you. Wrap the tape around bottom edge and make sure it is on the corner edges also. You might get a small mark here or there on the door, but not as likely.
The second common area is the clam in the front from the license plate mouting surface, around the front wheels. I like to wrap the front yellow plastic reflector on the wheel well also as a protection from a direct cone hit.
The other place to put tape, is across the front turn signals. They tend to pop out in case of a direct cone hit (they do on my car anyway) and a bit of tape across them should hold them in.
While I am on that subject, it is a good idea to pop out your front turn signals and using a knot, shorten the harness. The idea is that, in the possibility of your turn signal popping out, it just hangs, not drag on the ground and bang around. Use a screwdriver through the front grill to reach the plastic tab towards the front to release the turn signals. See page 143 in your owner's manual.
Another thing that seems easily damage if you go crazy and hit a lot of cones is the engine ducts on the bottom of the car. Cones will shear them off and you will find the duct laying somewhere back on the course. The ducts are cheap, but some preventative measures could stop this... like some adhesive or again, blue tape on the leading edges of the exposed duct bits. I pushed all my ducts backwards as far as they go and then globbed on some RTV to help hold them in place.
One other place to be aware of. Sometimes a cone can get stuck between the front tire and the mudflap behind it. Be careful about pulling on the cones. The mudflap attachments are really not designed for this...nor direct cone hits. They use these little screws in expandable rubber bushings to fill a hole in the fiberglass. After some experimentation, I find it best to just use an RTV or silicone cement to attach the mudflaps to the clam. The small screws are not enough for cones.