I'm almost in the same position as plisken, I'm not in any rush to sell/trade my M3 LR. I've had it almost a year to the day, it's the updated model built in China with rear heated seats, steering wheel, heat pump etc.
I paid a fairly chunky deposit, and have around £38k outstanding on finance.
I (unfortunately) am a serial car changer, just get a bit bored and like to try different ones. I enquired about a 2018 911 last week, best offer was £34k. The dealer struggled to get anyone to take it, motorway offering £26k etc.
So to change, I'm £4k to get out of the Tesla, will have 'lost' my deposit and would need find another £10k or so to keep monthlies reasonable.
I get PCP. I do not ever think that if, by some miracle, I make it to end of a PCP deal there will be equity in any car. I don't bank on it anyway. I also know that trading a new car after 12 months is financially daft, and almost no matter what car I had bought I'd be in the hole. TBH £4k isn't too bad. I bet if I'd bought a new M3/4/5 that figure would be WAY bigger.
It also isn't helping interest rates at the moment are high, best I could get on a lease purchase for a used car was 10.9%. Even a straight loan not is up around 5%.
Thankfully I like the Tesla, and will definitely keep it for another 12 months. I never make good financial decisions when it comes to cars but I'm just not throwing £14-£15k savings away just to change it as I get bored.
Wait another 12 months and I think it will all look a little better, values will have flattened out and finance will be cheaper (maybe not at pre-covid levels but it's likely as bad as it gets just now).
I'll be looking at a Taycan, 911 or new M2 I think
Just hang in there, could be worse you could have bought Tesla shares 12 months ago