Another concern is the sheer size of the proposed deal.
The largest buyout to date, the takeover by Kohlberg Kravis Roberts of RJR Nabisco in 1989, was worth $64bn in today's money.
Yet Mr. Musk may not need the $70bn-80bn (including nearly $10bn of debt) at which Tesla would be valued at $420 per share.
Some reckon he would require less than $40bn in financing if his own stake (about a fifth of the firm)
and those of other big public investors were rolled into the new entity.
Mr. Musk has given no details of where the cash will come from, but the source might well be foreign.
Tencent, a Chinese internet giant, already holds a big stake in Tesla.
Japan's Soft Bank, which has thrown vast sums at technology firms through its Vision Fund, might be keen.
But the most likely investor is Saudi Arabia.
Reports surfaced this week that the oil kingdom's sovereign-wealth fund had bought shares in Tesla worth around $2bn.
Even if Mr. Musk can rally the moneymen, going private may not prove a smooth ride.
There may be political opposition to large foreign investments in an American car firm.
Many punters who have held onto Tesla shares through the dark days made clear on Twitter that they did not want to sell.
Mr. Musk promised this week to create a special investment vehicle that would allow them and employees to "remain shareholders",
but experts say such an unorthodox and complex arrangement may hit legal snags.
Then even Tesla's accommodating board (which has already discussed this proposal) might be forced to reject it.
Public or private, Tesla will keep Mr. Musk running at full tilt.