mine was about 15 infront of my house because i had already left my house and had to back up and get my phone.

 

Not really sure what the fastest I have gone is in reverse since I don't really go long distances that far, backwards. Probably around 15 to 20 though. Definately over 10 since I have peeled my tires in reverse on several occasions when my rear tires were getting close to bald.