From my experience:

E90s are airbridge-d at MAD
An optional bus meets the back steps of T4 non-Schengen arrivals with the facility to transfer onwards to T4S without going through the tortuousness of passport control, interminable terminal, and train. Not sure if it's the other way.

Hi stifle, thanks for your reply! Just to clarify - I get off the E90 via the airbridge into the terminal, then from there, look for a bus to take me straight to T4S? Or exit via the backsteps of the aircraft straight onto the bus?

I don't know exactly as whenever I've used an LCY-MAD or v/v service it's been T4S. When I've done LHR-MAD on IB it is a case of exiting via the back steps.

LCY-MAD-LCY now uses T4 since mid-Sept.

If I have an ex-EU TATL business fare, but with the EU<>London connecting legs booked in J, are these connections changeable (and if so, what's the fee)?

J is just the booking class and does not mean it is fully flexible. Conditions are governed by the fare rules (presumably something like ILR28AP) so you will need to look at that to determine how flexible it is, and what the cost would be.

When I flew LCY to T4S they did not put on a bus, and my feeling is that is an IB metal special, bearing in mind their focus on getting people onto Latin America's long haul services. It would not make operational sense to provide such a bus for BACF from T4 to T4S since overwhelmingly most passengers, of a relatively small load, would be point to point, or at most going domestically on IB. In which case the new arrangement is great.

Therefore I think you're going to plan on using passports, walking to the transit (T4 is absolutely vast), passports again, then taking the lifts. Incidentally they seem to "simplify" the airport, so you will probably be looking for zones off the passenger information screens, it's not as simple as saying "this way to T4S", more like follow the signs to zone M, R, S or U.

It depends on the underlying fare rules but a typical change fee is €300 plus fare difference.

I think the second bit may be the killer for an exEU as I am guessing the particular I sale fare ENTP booked under has long gone so do they reprice it at the current prices? If so then it will be expensice to change!

That, too, depends on the fare rules and what you're trying to change.

Often the rule is that if there's a change to the first fare component --> reprice at current fares; if the change(s) do not involve a change to the first fare component --> reprice using historical fares if cheaper.

Ah, ok thanks for exaplaining it - I was reaching the limits of my ignorance on the matter which I think you may have spotted ;)

And another variation is reprice at current fares if the first leg has not been flown, otherwise reprice at historical fares.

Mostly. The T4S lounge is one I miss.

Thanks all. I was mainly curious whether J on the return leg (the infamous final segment) would be more likely to be offered a rebook to an earlier flight if turning up at the airport in good time, than the more restrictive booking classes.

I'm trying to convince my wife to do an ex-EU, as there are some incredible fares right now. I want to do DUB-LHR-MIA return with a car.

Day 1
Morning positioning flight to LHR-DUB
Day in Dublin (neither of us has ever been)
Start main trip in the evening: DUB-LHR
Return home to SW18 for the night

Day 2
LHR-MIA

Last Day/next as overnight flight
MIA-LHR
Wife to go home, me to do LHR-DUB-LHR

Before I book, I just have a few questions.

1) Can I call the UK Silver Line to book this (i.e. an ex-EU with a car booking)? With the overnight, I can't make it work on ba.com, but would gladly take advice here. Flights on aa.com are much more expensive so that's out.

2) Is this itinerary workable - i.e. safe enough to ensure I make the evening flight on the outbound?

3) Do I need to take my baggage for the main trip to DUB to check, or can I take it to LHR on day 2?

4) Can I avoid having the bags checked through to DUB on the return? I want to get the LHR-DUB-LHR bit done that day. I want to do it for the TPs, so don't want to faff around heading over to LCY. It's not a problem if not, we'll pack carefully and I'll have the bag checked under me.

5) If MrsGM and me are on the same PNR, will it cause a problem if she sacks off the last leg?

6) As the car makes it a holiday, can I UUA to F (it would be on AA) if seats come up? Do AA sometimes release seats close to departure, like BA?

Thanks!