Okay slightly outside of Tech Talk forum, but...

What are you guys doing when you paddock in a grassy area to create a "work surface" under your car? I'd like something suitable for jack stands and also for preventing the inevitable dropping a bolt or nut into the grass.

I've been thinking of buying some sheets of 3/4" plywood, but it seems a jack stand could break thru that if tilted etc. At a minimum I've been thinking of getting a big canvass tarp.

The last race at Mid-Ohio with rain both nights really made it hard to even get a jack under the car.