In reply to rachelpearce01:
It's a great idea! We just brought our car down through Spain, and it seemed relatively straightforward. Algeciras to Tanger Med is reportedly the easiest crossing from a vehicle import point of view, and certainly we had no issues.You'll need to have a copy of the V5 registration certificate with you, and it's best to fill in the import paperwork online. Here is the link to the form you'll need:
http://www.douane.gov.ma/d16ter/formAT.jsf
Once you've cleared customs (can take a while) you'll leave the port area and there are a line of small offices in the car park on the left... you'll need to stop here to buy temporary insurance if you don't already have a green card. It's quite pricey, but chances are that you'll get asked for proof of local insurance at some point during your stay. You can get it at the port for 1 week, 2 weeks, or 1 month. After that you'll need to get a permanent in-country insurance policy.
If you're driving down from Tangiers then you can also check out sport climbing at Ain Belmusk, and bouldering at Oukaimeden on your way down - both near Marrakech.
And yes, the Anti-Atlas is a perfectly safe place to hang out in a van near the crags.
Drop me an email if you need any specific info