It is my understanding that websites very rarely keep a record of anonymous accesses. Any retained data is kept on the Users computer in the form of cookies and cached data.
I use Firefox/Mozilla and daily I go through the cookies deleting all those that do not contain data I wish to keep like login passwords. I have also set my cache at zero megabytes. A number of newspapers that seek to limit free access are thus thwarted in their task.
If you request a "quote" by entering data into a form, by submitting it you have in effect registered an interest which is logged against your IP address. My local library provides 30 mins of free time per login for library registered users. It might be worth trying there if you have such a facility.
I run a couple of webservers in-house. Both utilise Awstats for analysis of traffic and I also get to see the raw access logs from Apache. MAC addresses never get a mention. No such data is passed to the server in a "wget" command.
You cannot change the MAC address of an interface. The MAC address is a hardware address encoded by the manufacturer in the chip used by the interface.