2 New Coils and Still a problem

I have replaced coil plug #2 and #6...also replaced the Fuel FIlter. This is a 1998 Lincoln Towncar Signature Series which, I still have a problem at 35 to 45 mph I get a double hestitation, I do not stomp down on the accelorator. What is happening, is it another coil ?

Diagnosing what you've described, without actually witnessing the hesitation is nearly impossible over the internet.

I do have some observations to bring up:

Since you've gone through the expense of replacing coils, I'm sure you've also replaced ALL spark plugs as well.

Was there, or Is there any OBDii codes present, indicated by your CEL (Check Engine Light) is on?

Are you absolutely sure it's the engine hesitating / missing? This symptom can be easily mistaken for a Transmission "Shudder", that normally occurs at the speeds you referenced. Some describe the Trans. shudder feels like the car is running over small ripples in the pavement.