As a matter of fact, such a mod already exists.It is called Back To Reality and was part of my inspiration for this mod. Back to reality is a collaboration of script mods made by that mad genius CNS. One of them allows you to purchase gas at the gas stations in SA. If you know anything about scripting, you can just use the source codes as I did for the gas. Heres the link to it:
RiZiNgdRaGoN
joined
This member has provided no bio about themself...