1-To remove all items from back of the dove tail you must do so through the tail light openings. These include bumpers, back-up light, and emblems.
2-An exhaust leak, (smell) may be caused by the absence of seals of the tail lights.
3-Never over tighten the screws that secure the rear tail housing or lens. They will crack if you do.
4-Replace the bulbs in the rear side markers when you have the tail lights out. Saves time in the long run.
5-Check tech tips (via Internet) on how to remove fuel filter sock screen from inside gas tank. These are usually clogged-up with junk. Replace with new inline filter. This will insure a steady flow of fuel to the carburetor.
6-To drain rear-end remove the bottom bolt on rear-end housing. No need to remove the cover. Replace gear oil using a good oil.
7-Adjust or replace rear brake linings today. They are usually neglected. You will be surprised at the difference in braking action.
8-Adjust parking brake today. Never know when you will have to use it to stop the car.
9- Replace entire rear end assembly on 68-70 GT's with a 71-73 assembly ASAP. Pre 71 rears are very hard to find bearings.
10-You must have an obstruction wrench, (15 mm) when removing the transmission, (4 speed).
11-Buy a pilot bearing remover to remove the pilot bearing from the flywheel. It is worth it's weight in gold when you have to do the task.
12-Always check all rubber boots and seal on the front end every time you change the oil. They fail often. Thirty year old rubber is very frail.
13-REPLACE THE HEADLIGHT WIRES NOW. SOMEDAY YOUR CAR WILL BURN TO THE GROUND IF YOU DON'T REPLACE THE WIRES. Check on the Internet on how to do this.
14-Add fog lights to your car. Opel GT's are small, and are hard to see. Any additional lights will help you in being seen.
15-Replace standard headlights with Halogen headlights. 100% increase in performance of lights.
16-Install split-fire spark plugs number SF 412C, big improvement.
17-Install K&N air filter in stock air cleaner, big improvement.
18- Install elec. ignition, big improvement and no more points.
19-Install Weber carb, big improvement.
20-Install new spark plug wires. Easy and cheap.
21-Install a bigger alternator if you plan to add lighting or a powerful stereo.
22-Change engine oil and filter every 2k or 2 months which ever comes first. I suggest using a good 10w-30. Sooner if you think you need to. I also check the transmission lube every time I change my oil. My transmission leaks a bit so I like to keep an eye on it's level.
23-Install one of those see through gas filters. This way you can see the element and check for clogging.
24-Install 3-point seat belt system for both the driver and passenger. I feel a bit safer in my car with them. Seattle traffic is murder.
25-install an armrest in your car, JC Whitney makes a really nice one that fits like it was made for a GT. I like a little extra comfort and a little extra storage.
26-Always carry an extra fan belts, extra fuses, tools, a cell phone, an extra clutch cable, and be sure your spare and jack are in good order.
27-Install a good CD player.
28-Use the Internet for any help needed.
29-To get parts needed in the upkeep and maintenance of your Opel GT you can not beat Opel GT Source. They are fair, friendly, and will always help you with any problem you might have. These are good guys that love GT's.
30-Join a GT club in your area.
31-Join the Opel GT group on the Internet. These guys know it all. Your best source of info bar none!!!!!!
32-Have fun with your car.
Drive safe. Keep smili'n. This list by Gary Samuels