A microSD card is 165 mm^3 = 1.65e-7 m^3.
Dividing one by the other: 15090909 microSD cards could be put in the car [This is simultaneously probably unrealistically high due to the assumed ideal packing and also low due to the large amount of space left in the car].
256GB is the largest microSD card I can actually buy: This is gives us 3.8 exabytes of data hurtling down the highway.
How to efficiently load/unload this data is beyond me. (Short of magic wireless microSD).
V unira'g purpxrq nal bs guvf, V'z n ovg qehax.
If it takes an hour to get to your destination (ignoring load/unload time), that’s an aggregate data rate of around 1000 TB (1 PB) per second. The entire Internet averages something like ~25 TB/s, so our Tesla X has the bandwidth of forty Internets.
Of course, there’s a downside: that many MicroSD cards would actually weigh around 3.7 tons (at 250mg apiece), which is heavier than the Model X itself! Might be harder than expected to make the drive itself.
Relevant XKCD (because there always must be one): https://what-if.xkcd.com/31/
Assuming it takes about 3 weeks to turn around, my arithmetic says each truck has a bandwidth of about 460 Gbps.
"Q: How do I connect my data center to Snowmobile?
Each Snowmobile comes with a removable high-speed connector rack on wheels with two kilometers of ruggedized networking cable."
Today, the equivalent may be an autopilot Tesla Model X full of microSD cards. Terabyte-per-second calculations left as an exercise to the reader.