Hi, as others have said its always better to walk in on your feet, rather than letting your fingers do the walking, if for no other reason than letting them see a big fat commission walk out the door.
Now as for deals, I found this on the www. It’s a starting point
Mellons Bangor: Offers up to £250 Motability Advance Payment Contribution / Cashback for Hyundai Models.
As for you ordering the car, once ordered mb ops will swap your vehicles over as soon as the new one is ready. Be that sooner or later than your hand back date.
Please check with mb ops, I’ve always found them really helpful