IF the kia does everything you need and does it well, I wouldn’t be changing unless your personal insurance is particularly high for some reason. Motability does offer good value but it isn’t even close to free. Even with a low AP the car is likely to cost you well over £12,000 over the three years. I know you say the money isn’t an issue but it’s a good chunk of change to consider.
If you think you’d benefit from something different, eg larger, auto/manual etc. consider changing but even then, I would be very tempted to wait and see what October brings as we have just seen a horrendous spate of advance payment increases this quarter and hopefully that will change next quarter unless you can find something particularly suitable and cheap.
If you go new, you may have to look for something in stock or with a short lead time. First time customers have to have a full 12 months left on an award to start a lease and I’m not sure if they would be OK with you starting a lease with less than the year remaining. The fact that the award will almost definitely be renewed after SPA may not matter to motability.
If you don’t NEED to change, I personally wouldn’t. If suitable for your needs, the current car is new enough to expect decent reliability.
"Man is born in freedom, but he soon becomes a slave, in cages of convention, from the cradle, to the grave."