You can use your credit card without any issues whatsoever!
Just go to the link and select your level... and choose "order", then click on "Order Using PayPal"... and you'll have the option to use a credit card.
Immediately after submitting I was upgraded on the JeepGarage.org site!
I'm sure they will appreciate your support!
Thanks, Jim. It worked just as you said with a credit card. Glad to be able to support this site.