Fluid additives are generally not needed. They sometimes cause more harm than good. As I mentioned earlier, in a prior tech tip, transmissions contain dozens of seals. Some are metal clad, some are lip type. Others are square cut or o-rings. The seals get hard and brittle as they age. This causes problems. Slippage, external leakage, etc. The purpose of most trans additives are to stop leaks or eliminate slippage. They ingredients in the fluid additives are designed to soften or swell the seals. Sometimes they actually work. Sometimes they work too well. Alot of the time, someone thinks"if 1 can is good, 3 cans will be 3x as good. This causes the rubber seals to soften excessively and grow bigger than their normal size. This normally kills the trans dead.
In summary, I personally would not use a can of liquid miracle. I would perform regular trans fluid services instead. If I had a trans that was slipping, and I was convinced the end was near, I would use no more than 1 can of "miracle cure". In that case only, it may be worth the $5 . Sometimes it actually buy a little time.

For what it's worth, Lubeguard is the fluid additive name brand I prefer. They are widely accepted by the transmission industry as the respected leader in their field.

i know i need to get my filter changed out this year

TTT