Interesting, the Tesla S and X figures for Jan 2019 and Feb 2019 don't match this reference. Tesla Model S US car sales figures Tesla Model X US car sales figures
I'm surprised the Prime's sales are so high with a maximum rebate of $2500. I bet most of the sales are in CA. I looked at December and the rebates on the east coast were up to $5000 but only $1500 in CA. I'm surprised the Clarity isn't doing so well with $6000 on the hood in CA and OR.
Tesla, and now GM, reports their sales figures quarterly. Monthly figures from others are educated guesses. The more efficient drive train for the S and X just became available, and the S is still getting a refresh.