It's all pretty & spray undersealed as far back as the rear axle box. I had a look underneath today when I took it back for the brake noise. Turns out that was a stone & a bent splash guard, I've never known a stone stay in for over 100miles before.
I gave it a squirt & then flicked the cruise on at 70 & left it there, except for the bits of the M62 limited to 60 because they were pretending the gritters were out. I don't bother rushing on main roads, too many cameras & no fun. I did overtake someone in a new XJ between the pub & the M62 on the way back. He was driving embarrassingly slowing for a Jag so it had to be done.
Before it went in the RH bank was trimming about 10% rich from the ODBII readings, when I cleared the codes earlier both banks were about 19% rich. I'm assuming/hoping it'll behave better once it retrims it's self. I could speed that up by disconnecting the battery but doubt I'll actually bother to carry a spanner that far.