Top Gear as it stands should be thoroughly revised. The rot has set in a long time ago, and it's affecting the presenters' specials as well. See the 3rd episode of James May's Cars of the People as proof, as there's a lot of contrived for-the-sake-of-laughs cack in it as well.
It feels like they are deathly afraid of there ever being a boring moment, so the show is written to constantly contain pretty redundant japes and quips which result in stuff like the Slopegate. Who cares what he said? There's just the inbuilt need to entertain the percentage of audience who couldn't care less about the cars and only want to see the three blokes as caricatures of themselves, and that results in Clarkson acting like he's holding up the '30s British Empire singlehandedly.
When we visited Romania on our FG roadtrip, it became obvious how they had to massage the script to be more interesting, like they completely accidentally slept in their cars next to the enormous dam, on a side road where you would need to purposefully drive a while to get to. And who believes you would ram a random local Dacia all of a sudden?
LOL... Yeah, there are plenty of times since maybe around series 10 or so where the scripting was painfully obvious and then it was like they realized it, got better and then it seems to have ups and downs. The show has always been scripted to a point and I don't think there is a way to genuinely get around that, but it did seem to get lazy for a time and then here and there, etc. When it comes to the Romanian episode, I think they are well aware that the audience knows all that stuff was a put on, especially the Dacia... They beat the "Good News...The Dacia Sandero..." joke to death and then gave it a comedy send off during an otherwise uneventful road trip. I think the producers thought it was a good idea to do Romania and then realized "oh crap, we need filler..." HAHA.
Back in series 10, the "Space Shuttle" episode was far-fetched ONLY when they talked about landing the car. I swear the explosion on the ground went off split seconds before it would have on impact and I just think that they knew they couldn't land it properly, so they wanted to go out with a huge bang rather than see a Robin just fall from the sky with no drama. Sure it would be funny, but series 10 is when they REALLY started going global, so there you have it.
The fact still remains that they DID launch it and it really was breaking records like the rocket guy said... I always wondered if Clarkson didn't want anything to do with it because they knew that landing wouldn't work. Who knows, but staged or not, that was still really funny.
Going back to the Winter Olympics and comparing the parking at the dam you mentioned, this is nothing new... After all, I know of no MP5 that can saw through a tree in one clip... LOL
Even Clarkson laughed when they won the Emmy for "Best Unscripted Show" or whatever it was and then said something about the script for that show... LOL.
I don't think they are trying to pull the wool over anyone's eyes, but rather create a weave of scripted and improvisation comedy intermingled with automotive facts, goofy challenges, etc.
What I don't agree with you on would be what you said about "thoroughly revised"... I just think that they simply need to broaden their factual reviews just a bit and get more creative with the challenges in certain ways... There are other threads for that, but one huge thing I miss from the earlier series is how genuine the laughs and general BS was during the news... The news remains my favorite part of the show and I can't stand how they neuter the news out of the show when they air it on BBC America and even on Netflix...