What does your credit look like? If you're just coming out of school I assume it isn't yet 'Excellent' at this point -- so you'll have to factor the (likely) higher interest rates into loan/lease payments you're expecting, or co-sign with your parents to lower the rate.
You're onto something with your Option 3, and also your stated desire to do a Euro Delivery.
Allow me to suggest
Option 4:
Drive the Lexus through the winter, into the spring when ordering for the M4 coupe will likely begin. Use the down payment your parents are giving you, along with at least some of your 5-figure bonus check (maybe 1 of the 2) towards the M4, and order it for Euro Delivery. Doing that will allow you to get it from Steve Thomas BMW or another board sponsor for around $500-$1000 over invoice (if history repeats, and I see no reason why it won't on the M4), because ED orders generally do not come out of dealer allocations. This will also reduce your invoice price by 7% over what it would be for a normal US car. On my 2013 M3, that savings was approximately $5500 -- which covered my plane tickets, and hotel stays in Munich. Can you say free vacation?
-- You'll also want to take the loan (not a lease) from BMWFS, even if you don't like their outrageous 3.5% rate, because it'll net you another $1500 in your pocket. You can refinance in 3-4 months and get a better rate elsewhere, but you still pocket those savings. Depending on the down payment amounts and your options/pricing on the M4, your monthly payments could be as low as $500-$750 or so, which should be affordable given the figures you've posted. Finally, doing ED removes any 'drive-off-the-lot' depreciation usually associated with a new car purchase, because of the 7% invoice reduction, so it's the best of both worlds. After the loyalty discount, the BMWFS discount, and the ED discount, I got my new M for what some other threads here are currently asking for 2011s
Best of all, you'll be one of the first of us here on the forum with a shiny new M4
