Car insurance for DTs, gulp

[truelymadlysleepy]

DTs 17 soon. We've bought them an old banger as the quote for my car was £7K.
I'm getting confused with quotes.
Some companies quote for provisional learners only, some quote for the 1st year including for when they've passed their tests. Some won't quote until their actual birthday. I'm struggling to compare.
I definitely want them to have a black box and am keen for them both to do Pass Plus.
I understand that although the car belongs to two people only one can be the owner keeper.

Any ideas? It's driving me nuts and they haven't even started to learn yet

My DSs age 18 and 17 share a car. I am the owner and registered keeper. DS1 is the main driver. Having DS2 on as an additional driver added £500ish to the premium - £2200 for a 1l yaris which I passed down to them. I went with a policy where price didn't change when they passed their tests (direct line) and have a black box. DS2 does earn no claims discount too but only for use at Direct Line.

Thanks. I'll give Direct Line a call.
It's such a minefield.

DD was insured by Admiral last year when she was 17 and just passed her test. Cost £1500. Black box kept her very aware of her driving. I have just renewed her insurance for £630/10 months. Very happy with that.

Different cars have different risks. DD has a Ford Ka which seems to be a bit of a girly car so statistically lower risk.

Thanks all, it's been a nightmare with 2 learners on one policy. Just in case anyone else is in the same boat I've gone with iKube which covers for the 1st year, Provisional then Full License.
£1800 though.