So, what you're saying is Corrie was having an affair with a married woman, who was around the same age as himself (23) and should be in the honeymoon phase of her marriage...maybe has young kids too. Her husband happens to work nights...handy, that. Rather going straight round to her place he gorges on two cheeseburgers, chips and a smelly kebab...after drinking himself into a near stupor...slumps in a doorway for two hours surrounded by smelly food packaging...then phones his married lover at 3:00am because he's feeling soooo romantic...she gets out of bed...drives to collect him while he's all smelly and disorientated...then drives him back to her place (without either of them or her car being spotted...have rampant sex....then suddenly her husband comes in....he kills Corrie....and they've kept his body in the house for 8 weeks? Or carried his body out of the house without neighbours seeing and dumps him somewhere? Seriously?
In my experience that sounds absolutely reasonable as far as what men are like lol For a first date, no I don't think so, but for someone he's been seeing a while? Totally normal man behaviour.
What I actually suspect is that the hubby was called away for some reason, and work seems likely. He'd kind of have to be out of the house for this theory to work. Why not spend the evening with her instead of going to the pub? I don't know, there could be a perfectly simple explanation, she might have gone out somewhere else and Corrie couldn't go with her as they'd want to act like a couple but couldn't in the company they'd be in.
I see her as maybe being a couple of years older than him, and people of any age can have relationship problems, even within a few months of marriage.
So her hubby's called into work and he's not expected back until later on Saturday morning. She goes out to a get together with friends but can't take Corrie with her because her friends know her hubby too well. Corrie goes to the pub. But his evening was cut short, he had his food, he's had too much drink to drive, his mates have probably gone home without him (because he fell asleep). So he messages her and says he really wants to see her and to come pick him up or he'll have to sleep in his car or walk back to base (spins it thick with puppy dog eyes). She's crazy in lust, so she goes for it...it's 3.30am, neighbours aren't likely to see him going into her place, and sneak Corrie back out early in the morning before hubby gets back. But hubby gets back early, or they both fall asleep and don't wake up until the door opens and heavy footsteps walk in.
They can't hide a body in the house for 8 weeks, it probably goes Saturday night under cover of darkness, just pull the car up to the door and it's doable. It's been done before, there will be hundreds of stories in this forum where it's happened. There are far nastier and sicker things that sounded way more implausible aplenty in this forum.
Was the car seen? I can't see how it could have been missed if it actually went into the horseshoe, and I can't think of a valid reason to drive down there at that time of night, but if you can make something up, what can the police do? Without evidence of a crime, there's nothing they can do. But if you give them time, they can get that evidence, whether it's this or something else behind Corrie's disappearance. Get the right witnesses to come forward to time Corrie's disappearance from the horseshoe, time that to the appearance of the car, follow the car around town and maybe find an image that can be enhanced to show someone in the passenger seat with blonde hair and a light-coloured shirt...find a body, and then you've got a warrant to search the house and car and take the couple in for questioning. It might take another month or two but it can be done.