Thanks for your question!
If you go to booking.carrental8.com/ and look at the top of the page on the right you will see a tab that says "edit booking".
If you click on that tab you should see a place where you can access your booking. Just enter your reservation number and the misspelled version of your email address - firstname.lastname@example.org for the email address then hit the log in button.
You'll get access to the Account Access Portal which will allow you to view your reservation and there should be a link on the top right to View Voucher - which will tell you which company your rental is confirmed with. You may be able to print the voucher from there.
If you need to have the email resent, then look to the bottom right hand side of that page and you should see a green CHAT NOW tab. Once you get an agent, just ask them if they can modify the email address on your file and or send you a new confirmation email to your correct email address.
Hope this helps!