Hi D. Locke. I'm curious what non-existent variables you are referring to specifically. Do you mean like, no puddle of radiator fluid found in the parking lot? No witnesses of anyone around Sue's car while she worked? Things like that?
With genuine respect, because I've gone down a few dark alleys with various theories myself, your own theory relies on at least one key variable that doesn't exist and that's a question of the credibility of the gas station attendant.
From everything we have from Susan's family, from Washington County Sheriff's Office, from the gas station clerk's interview in a well-done podcast, and from others, she has been cooperative and credible and helpful for these past 38 years. Have you listened to her voice in her interview with Kara Thannert? Have you listened to what investigators and others close to the case have said about her? Have you listened to what Sue's sister said about meeting her? I can provide links and transcriptions if you haven't seen or heard this stuff. If you have heard/seen it, I'd like to know what you make of it and why you don't take it into consideration.
I believe your theory makes an unsound accusation that the gas station attendant was an accomplice of Sue's abductor. You might just be caught up in one of those circular logic loops these things can lead us into. I'd like to know more about what your reasons for believing the clerk is protecting a false narrative are. It's not supported by any of the credible information that's been published. If it comes down to the changes in what she recalls about that night, I really think she is legitimately memory-challenged. Even Sue's own family has problems recalling things exactly as they occurred 38 years ago now.
I believe the initial investigation by Washington County Sheriff's Office in 1988 failed Sue and her family and her community. I also believe Washington County Sheriff's Office is painfully aware of that and they have done everything they can since 1998 to make amends and bring this case to a solid resolution. There's no doubt in my mind that if they had questions about this gas station clerk's credibility that it would have come through somehow in the way this story has been reported, and that they would be right on top of it. She would have become a "person of interest" to the case a long time ago, or there would be a lot of tap dancing around any discussion of her in the press or in podcasts. We just don't see that sort of thing happening around her.