. . . The joints between the plastic/poly/whatever interlocking tiles. I'd call them "liquid Resistant", but not 'proof'
On the other hand, you would leave them down for a Very Very long time, so any discolouration under them (?) would not be an issue, IMHO

Leaning towards 'Driveway Paint' only for economic reasons, and Sarah might not be part of our fleet for much longer...

- The other cars do NOT leak or mark territory...