I recently parked under a pecan tree at my house. I woke up the next morning and about a dozen pecans fell on to the hood & split open. I power washed it immediately - but the stains remained. I've tried scrubbing, with a microfiber cloth & then using a clay bar and it's not doing jack shit.
On the other hand, my wife had the same thing happen to her (sliver jetta) and the clay bar method took the stains right over her car. Any advice or solutions would be welcome.