Hi Des!
If you click on "Join the Club" at the top of the screen and choose either the one off subscription or the auto-renewal, you'll get taken through to PayPal. It's only £10 per year, and as soon as you've paid, your account is automatically upgraded, so you'll have full forum access.
Link here also - http://www.mr2mk1club.com/payments.php
I'll then send you a membership number within a few days, which you can potentially use with your insurance company to get a discount if you mention you're a car club member.
Any other questions, just ask!
Cheers,
Tom