Yes, 4.5% rates suck.I believe it's the 12k FSD and the 4.5% current interest rate. I'll make extra payments after emergency savings are attained and will re-finance as soon as interest rates drop.
Why am I so passionate for FSD you may ask? One word: 'Timecop'
I have FSD (Beta) on my 19 M3. I paid $6k back then, and it is fun now ... sometimes ... when I have time for it. At $12k - it just doesn't make sense to me. My advise, skip it, you can always subscribe for FSD for a month ($199) when you want/need it. As of now, 12k = 5 years of continuous subscription. Please understand that for $12k you buy a privilege to test FSD for Tesla, you are not buying a [more or less] finish product.