I’m guessing the monthly payments are still higher with the GT, but how much higher? I didn’t see that in his posts.
It's a fair question, so I'll try to break it down (apologies, there's a lot of detail).
Plan A (discounted i4, with no fixed price part-ex for my current car and no time-frame for delivery):
Originally, I signed for an i4 e drive 40 M Sport, with the Comfort Plus Pack, Tech Plus Pack, Portimao and not much more, @ 4.9%, £8500 in from me (to include the equity in my current car which the dealer and I estimated to be pretty much 100% of it as part-ex). With a negotiated discount, that worked out at
£750/month, which worked out somewhere around £50/month cheaper than running my current S4, having taken the personal loan, VED, warranty, car tracker and 'Audi Connect' (mapping and online services) into account.
Then BMW told me the APR was going up to 6.9%. If I'd stayed with that dealer, with negotiated discount, they could at best do my existing order for
£816/month (£66/month more that I signed at 2 weeks previously). Concurrently I'd put together the ideal spec using the BMW online configurator and finance calculator, (adding Tanzanite and Laserlights), working out at
£798/month @ 4.9% and around
£862/month @ 6.9% (again with negotiated discount and not including the recent price rise and potential subsequent price rises prior to delivery). With that dealer, they wouldn't provide a part ex value for my car (due to the long wait in build times which was fair enough).
Plan B (i4 inbound to dealership in Sept '22, no discount, initial quote now based on 6.9% finance, fixed (reduced) price for my part ex):
I then contacted another BMW dealership from a different franchise, who quoted (for the same initial car I'd ordered but now at 6.9% but with no discount as they weren't going to budge on price),
£873/month. In addition, they wouldn't be able to get a car to me before Sept '22, and advised that in their opinion my current car would lose at least £3k of it's equity by the time their i4 was ready. To get the payments from this dealership to match the revised payments from the existing dealership at 6.9%, I'd have had to put in a further (approx) £6000 of deposit to cover the reduced equity in mine (monthly payments change by approx £25/month for every change of £1000 change in either overall deposit or added/subtracted spec), along with the lack of discount from this new dealer. So 'new' monthly payment for an i4 with now effectively a £14500 deposit (including equity) was
£873/month (£123/month more than the car I'd originally signed for)
Plan C (etron GT, 6.6% APR, order inbound August '22, fixed price for my part-ex):
I'd contacted an Audi dealer who'd advertised a discounted rate for etron GT's with a Mar '23 build slot, and to my surprise they advised they had a cancelled order inbound, in 'almost' the exact spec that I'd originally wanted last year when I first test drove their demonstrator. When I looked at the value of my part-ex, they advised they'd lock in the value as it stood today (not the alleged £3k equity reduction between now and September quoted by the second BMW garage, nor the unknown value from the original BMW dealer). The GT residual value after 4 years is approx £20k more than my i4 spec over the same period, so whilst the MSRP's look fairly different (about £20k), the jump (and with the caveat of one is committed to the overall finance, not just the deposit and 4 years) in monthly payments isn't as much as you'd think for the portion financed over the 4 years, for me we agreed on
£851/month.
Long story short, if BMW had honoured the original 4.9% rate, that made the i4 very competitive over 4 years. At the revised APR but still with discount, I was looking at being £34/month cheaper (prior to the most recent price rise on the i4) than an etron GT if they upheld the value I wanted for my part-ex (unlikely given the waiting time for the order being stuck at Status 047). If I'd revised my i4 spec to the exact one I wanted I'd be looking at it being a minimum of £12/month (again that’s before the i4’s most recent price rise) more than the etron GT if they honoured a discount (and around £60/month more if they didn't).
Had I have gone to the alternative BMW dealership, I'd have been looking at £22/month more than the GT for my existing i4 spec and probably about £60/month more than the GT for my ideal spec'd i4.
One could argue there's a jump in deposit going from the i4 to the GT to get those numbers, a fair argument until you factor in the guaranteed extra £3k Audi were offering for mine + residuals + marginal difference in APR.
Summing it up (and apologies for the detail) but my initial deal with BMW was price sensitive, hence me confirming with them before signing whether I was price protected at 4.9% and discount (as otherwise the cost to change from my S4 made no sense, factoring in all costs including fuel etc). The fact that (and one can argue if it's fair or not), the subsequent increase in BMW UK APR rates and price increases just narrowed the gap on the finance between the i4 and the GT. Factor in the stronger part-ex value from Audi and it roughly breaks even on a revised price and rate i4, which for me kind of made it a no-brainer (purely personal opinion as the i4 is still a fantastic car

).
Hope that helps explain (sorry it's wordy, a lot of variables went into making the decision)