If your convertible top is malfunctioning due to low hydraulic fluid, the solution isn't simply adding fluid to a hole. You'll need to:
1. Identify the leak: Find where the hydraulic fluid is leaking from. This could be a damaged hydraulic line, a faulty pump seal, or a leak in the cylinder itself.
2. Repair the leak: This will likely require professional assistance, as it involves specialized tools and knowledge to identify and fix hydraulic system leaks. Simply adding fluid will likely be a temporary fix at best, and the leak could cause further damage.
3. Have a shop flush and refill the system: Once the leak is fixed, a mechanic can properly flush and refill the system with the correct type and amount of hydraulic fluid.
In short: Don't look for a fill hole. Look for a leak. Get your convertible top system professionally assessed and repaired.