I know this is a bad time to lease, particularly for German leftover loaner models, so I am seeking advice on fast cars that I will have the best chance of snagging for under $500/mo when leasing support is at its greater in the fall.
Btw, fast in my mind is under 5 seconds 0-60.
Which cars should I target?
540i loaner?
E400 loaner?
Charger 392?
Volvo of some sort?
I’m not interested in Infiniti, as I currently own one and not happy with it.
I don’t know about fastest, but some people were snagging some great deals on the Jag F-types (2017s I think). Some of those were sub $500, but they could be gone now.
The best thing to do is window shop through the Trophy Garage. Not all of those are currently possible, but it will give you an idea what was at one point possible.
Mustang GT 2020202020
probably challenger or charger scat pack
The fastest car in the world is a rental car with full insurance
You might be able find a loaner BMW 340i under 500.
I browsed the trophy page. That hellcat was a hell of a deal. Too bad nobody is still offering that.
I know its not the question, but the cheapest car under 300 p/m is the Challenger R/T
IMHO - the fastest one per $ spent, the following. The deal just gone earlier this week!
In-fact, the improved deal came to: $1983 one-pay for 15K/miles year, 2 year term.
If all you want is speed, the obvious answer is a muscle car. Probably the Mustang GT. The biggest downside, though, is you’ll have to drive and be seen in a Mustang GT.
I guess I should have clarified. Fastest, COMFORTABLE, car. I want something fast but need something comfortable, with very low NVH. I’m not super young anymore, so camaros and mustangs no longer interest me.
I doubt you can do a 340 let alone a 540 for under 500 bucks without any money down. Also no MSD. Under 5 second car im not sure, but TLX a spec probably under 500 with absolute 0 down is easy to get. I think its 5.4 sec car though. The only other would be the q60/q50 400 but u dont want infiniti.
392 is the fastest of the cars you listed, in order to find one of those for under 500 you will need to work for it but its doable.
I bet the Kia Stinger would probably fit the bill. I’m not sure how comfortable any car is that pushes a 5s 0-60. The only cars I can think of are the Kia Stinger, LIncoln MKZ or the Lexus RC. They’re all around $40k MSRP so you might be able to make it work. Or just get a 6-cyl Accord or Camry and settle with 6 seconds. 
The awd giulia does 0-60 in 5.1, you can find them under $500 pretty easily
You can definitely do a 340i for under 500/month. That is probably your best bet OP. Throw a JB piggyback tune on there and not much will keep up with you. Oh, and you might wanna swap out the runflats and put them back on at the end of the lease.
I dont think the RC350 hits 5 or under secoinds
For Beamer 340 or even some cheap 440s would work. 540 is a stretch.
Charger R/T Scat Pack has 485hp but brakes aren’t great, Daytona 392 has the better brakes though which is kind of important on a fast car. It is like driving a water bed though with stock setup. You’re not going to get anything close to that performance with that price point from a BMW.