Porsche 928

Remove the carpet from each panel. If your shark is going on 20 years old like mine, then it will probably be falling off anyway. Be careful as you do it though, since some damage to the masonite can be hard to spot. Best not to worsen the damage if you can.
Check for damage. Some will be obvious, some may not be, so spend a little time looking closely and poking and prodding. My left hand panel had the section above the split at the front broken off entirely, along with the main bolt hole at the bottom pulled through. The right hand panel was worse again, bolt hole pulled through and split, back end almost broken off, front top corner cracked.
Clean up the effected areas. Some moderate weight sand paper can be used to rough up the gloss side of the masonite and take off the old glue from the carpet.
Cut out sections of fiberglass for each damaged area and lay them out on a clean surface ready for use. I used 3 or 4 layers of glass on each area. Starting off with 4 centimeters overlap each side around the break or split with the first patch, then 3, then 2 with the subsequent layers. The number of layers required will depend on the weight of the glass you use. Take a small sample of glass and try tearing it apart. If it tears easily then logically use more layers. Remember its the glass that gives the repair its strength, not the resin.
Mix enough resin for the first section of the job. If there are multiple breaks like mine, then I would recommend doing the job in small stages. Takes longer, but it will let you learn bit at a time and wont give you curing trouble (more on that later).
Wet out the masonite on one side of the damaged area with resin. Make the patch about 1cm larger than the largest patch. I did my job both sides at once and found it caused me difficulty with handling and lay up. Take the first piece of glass cloth and lay it over the damaged area. You can use the paintbrush, or a small roller to work the air bubbles out of the cloth. Don't apply more resin at this point unless the cloth is showing obvious signs of not attaching and taking up the resin. Less resin is better as long as the cloth is fully wet. Apply the remaining layers of cloth adding resin if required.
Wash out your brush and other tools in thinners before it gets tacky, otherwise you will go through a lot of brushes.
Once you have the glass applied you are ready for curing. If its a stinking hot day the resin will likely be going off in the pot as you try to apply it. If its cold then things could still be floppy next morning. Resin cures strongest when warm, but not hot. One of the problems you may face is getting the glass cloth to sit flat over the repair. The best solution is vacuum bagging. This involves placing the work piece in a plastic bag then sucking all the air out. The result is that "atmospheric pressure does the work", squeezing down on your resin, glass and console panel. This has two benefits: 1. It drives out bubbles from the repair 2. It drives out excess resin from the repair. Both things result in a stronger, lighter join. For a small piece like a console panel you can try the vacuum storage packs that can be purchased from stores like K-Mart. They have a large opening to put the piece in, and a one way valve to keep things air tight. Just attach you humble vacuum cleaner to the nozzle and hey presto! a professional vac bagged fiberglass repair (note: you may want to line the bag with another plastic sheet before you put the work piece in, as the resin may attack the bag's plastic. I have found that glad wrap works well with epoxy).
During the curing process you may wish to splint or clamp the repair. Where possible I used light weight kraft wood wrapped in glad wrap, on both sides, held in place by bull dog clips. If you are vacuum bagging the job then they should be on the outside.
Find a warm place for your piece to cure. The resin should have instructions on it for ideal curing temperatures, but anything over about 30 degrees C will help. Personally I used my (electric, fan forced) oven set on ultra low
Allow the piece to sit in its warm spot (where ever that may be) for a couple of hours to "go off" (get hard). A couple of hours should be enough. However it wont fully cure for a day of so, so treat it gently until all your repairs have had at least a day to cure properly. Once the resin has gone off though you can happily work on other repairs on the same piece.
Once the fiberglass is cured you should clean up any rough edges with sand paper to give a neat finish. If you have had to patch any pulled through bolt holes then you will need to re-drill them. This is where epoxy comes into its own. Its far less notch sensitive than polyester resin. Over time the polyester repair may crack around the drill hole, epoxy is less likely to do so.
Recovering the panel is pretty easy. Clean up the carpet, as it will likely be covered in residue from the original glue used to attach it. A stiff brush should do nicely. To attach the carpet I used heavy duty, double sided tape. It was ok at the time, but I think that a contact adhesive (like Kwik Grip or other similar flexible glue) would be better in the long term.
Re-installation - The pay off! As the screws to hold my side panels in had vanished over the years preceding my ownership I was compelled to buy new ones. I added oversize washers to them to spread the load and help prevent them again tearing through the panel. You can paint them up an appropriate colour if you like, but I left mine bare, that way (hopefully) the next auto electrician who wants to get the panels off will actually see them rather than just trying to rip the panel out.
As you try to insert the panels note that the centre console has a special groove in its edges that the console panels fit neatly into. If your shark is as old as mine and the skin on the consol is coming away then be careful not to break or damage the skin while re-installing the panels. It will likely be brittle and liable to crack if pulled.