80th percentile household income in Santa Clara County is $200k/yr [0]. The linked dataset doesn't go any higher, but I suspect 500k/year is 95th percentile or above, which puts you in the upper class. Even in the Bay, $500k/yr is the "own two homes and a few Porches" level.
A $2.5m mortgage would cost you around $13k a month, Porsche lease less than $1k a month. You've got about $15k a month left in take home pay what in the world are you going to spend that on and still feel middle class?
500k/yr is around 41k a month. Figure you are going to be paying about 40% in taxes or 16,400 a month in taxes you get 24600 left
Considering you just spent 14k on a house and car you get 10,600k left. Groceries for a family in the bay runs around 2k a month so now you are down to 8k a month. Wife needs a car plus you need insurance gas and maintenance. Parking runs what $45 / day or 1350... lunches run around 30/day or 900... you haven't paid for clothes or extra curricular activities ( karate lessons 1k / month )
Family is not cheap, Family in the bay is hella expensive
plenty of people support a family on $60k/yr so take the remaining 440k minus taxes and buy two porsches outright. You should be able to save enough for a down-payment on each house given a year of saving.
that's besides that point? When you quote 500k/yr salary that typically includes perks like insurance. But are we really quibbling about $20k in expenses on a 500k salary? Even if I grant you 80k/yr to run your family that still leaves more than enough for your two porsches.
[0] http://www.vitalsigns.mtc.ca.gov/income