As far as “old runs being added to the leaderboard” there was a 2 week long backlog that I approved a bunch of runs for so that may be what you were seeing. There are still runs being submitted on the current patch that are beating old speed records.
Epic/Psyonix seems to be aware of this issue and is considering it a bug. Hopefully that means it will be resolved soon. Right now we are holding off on any leaderboard wipes but will be monitoring the situation. WRs are still possible on maps but are just harder.
@Soupsy there doesn't appear to be a great way to prevent it from happening at the moment. Epic is aware of the bug and is working on a fix.
As far as detecting if it has the glitch, there are some signs that point to the glitch occurring (ex: the start of race countdown not happening at a constant speed) but it's mostly from experience of either playing a bunch or watching a bunch of high level runs that it is apparent that something is wrong.
This is a glitch that causes the vehicle to move faster than normal. This extra speed is not visible on the speedometer. A speed-glitched vehicle going 570 kph will be moving faster than a non-speed glitched vehicle also going 570 kph. This bug occurs more frequently in old-gen consoles (PS4 and XboxOne) but can happen on any platform. This bug is not allowed to be used in leaderboard submissions outside of the named category.
If you submitted your run to a different category and it was moved to the speed glitch category it was determined by the moderation team to have the speed glitch.
See the latest news post here. https://www.speedrun.com/Rocket_Racing/news/vxp8256p
That's crazy how far it lets you go through the map border. How high was your ping?
Does the tutorial have a completion timer like a normal track?