Cash job, don’t mention it to the insurance companies (they WILL keep a record and hold it against you) no detriment to 3rd paties car value (stays HPI clear) don’t have to declare a claim for the next FIVE YEARS, with resultant premium hikes. Insurance companies are like bookies, they may pay out in the short term, but they will get it back off you in the end, with trimmings.
IMO, never worth going through insurance unless you can’t afford the lump sum outlay. You’ll pay for it one way or another, best just get it over with.
All hypothetically of course, because you are obliged by the terms of your policy to declare ALL accidents no matter how small so they have a justification to fleece you even more can protect you in the event of a claim.