I hear that the UK is trialling them in England an Wales, and London also had a trial run in 2021/22. Not sure what came of it, though.
Trouble is, the UK has no law limiting the noise a car can make. Only if there is e.g. a modified exhaust can the police even do something.
This is not true. See rule 123 of the Highway Code which says it is illegal to modify your vehicle to make more noise and that the noise of a vehicle should be below 86 db.
The current issue is that enforcement is not proactive and the fines are very low. Most police departments only issue a warning for first time offenders.
For an extensive review.