Driving in London

Ok so 707 Finchley Road is the Hertz dealership in Childs Hill/Golders Green and it’s a fairly straightforward drive down to the Hendon Way and onto the M1.

Whether taking the train is better depends on your overall plans. It’s two hours on the train from KIngs Cross to York and tickets start from less than £15. When are you travelling, are you looking at the correct prices? https://www.lner.co.uk/

Travelling by train, you could be in York stress-free and relaxed by the time you’ve barely reached the M1 from the car hire place.

It’s would be far, far easier to take the train to York.

Why not pickup the car at Heathrow?

We got stuck on the M25 parking lot for several hours. Never again will we go anywhere near London in a car.

I am wondering if I should change the reservation to pick the car up
in York and drop it off in Plymouth and take the train to York and
from Plymouth.

Yes! As mentioned, train tickets are not that expensive if you buy them in advance. And even if they were, I personally would gladly pay extra to avoid the London traffic.

If you start outside of central London, near a motorway exit, you should be alright. I rented from near Paddington Station which is quite central, but we were close to the A5 and just followed that straight of London no problem. Yours looks like a reasonably easy connection to the M1.

You can get to York from London for under £20 on the train.

I would not want to drive in London at all. Take the train.

The train to York is a 2 hour ride, driving will be 5 hours. If you plan on going on the M1 you won’t get to see any of the beautiful villages like you would if you took an A road. By taking the train it wouldn’t be stressful and your would be able to enjoy seeing the scenery.

Having recently driven a few times from Plymouth to (near) London, it's not a car journey I'd recommend if you want to get to central London, or even to Heathrow. Driving makes sense for a road-trip stopping overnight(s), along the way, but not a straight shot between the cities. Plymouth itself is a confusing city to drive around and it's not connected to a motorway. You either have to drive to the M5 and then onto the M4 (a busy route around Bristol and can be very congested as you get to London) or go cross country through Devon, Dorset, etc. By contrast, a rail ticket starts at only about £20, so not that expensive and a much quicker & more relaxing journey.

I don't understand the advice earlier to pick up the car at Heathrow in order to avoid the M25. To get to York from Heathrow one either has to use the M25 (at one of its busiest sections), or head back towards London and use local roads to get to the M1.

If you pre book a specific train near the time when the ADVANCE tickets are released - around 11 weeks in advance, you can go by direct Cross Country Train from Plymouth to York in around 6 hours for about £57. See this test that I just did for a date in April:>http://ojp.nationalrail.co.uk/service/timesandfares/PLY/YRK/110420/0900/dep

If you go direct to the Cross Country website - it looks like they will give you a further discount - BUT do not book an expensive ticket that appears before the cheap advance tickets get loaded for your date. .https://www.crosscountrytrains.co.uk

Going via London is a lot of hassle. Don't forget to also pre book your York to London leg - assuming you are returning to London. This can be done with Cross Country but they will not be your train company for this leg. It will probably be LNER. Check the fares on the nationalrailwebsite.

"Going via London is a lot of hassle."

I don't think that is what they are planning. I think they want to go from London to York and, later, from Plymouth to London. The section inbetween will be by car. So the question really is where to pick-up and drop-off the car. I'd recommend York and Plymouth, and do the two journeys involving London by rail.

Thank you everyone for your great advice. It seems almost unanimous to take a train out and back into London instead of driving.
I appreciate the help!

That's what I'd advise too.