My late friend Brian bought a new VFR750 from a well known West Yorkshire dealer who, at the time, was multi-franchise (they are now a solus mainstream European manufacturer dealer). After the first service, he noticed an oily mark on the garage floor underneath the bike & found the sump drain plug only holding on by a thread. This shook him up a bit, as he had been "excercising" the bike on the M62 on the way home from the service.
When I had a Moto Guzzi California 1100i that had to go in for (a lot) of warranty work, the dealer brought a loan Califonia EV in his van & took my bike away. As I pushed the bike into my garage, I could hear a cyclic rattle from the front wheel area - investigation found that the inner brake pad on one caliper was not secured by the retaining pins, but was rattling on the disc bobbins. I got permission from the dealer to sort the issue & found that quite a lot of the pad material had been worn away by the bobbins, so the situation had been present for a while. I didn't ride that bike much & checked mine over thoroughly when it was returned !