I had the same symptoms; losing signal every few minutes.I am a retired electrical engineer, and thought the most likely reason was a bad connection or poor continuity.The obvious place for this would be below the Ariel.I unscrewed the actual Ariel and found that it is a sealed unit and so eventually resolved to remove the lining and get to the base.I also wanted to check the connections at the first plug/socket ( that I could see from the parts photos online, were about 500mm away)1. first removed the tailgate rubber seal.2. using a large flat screw driver, pop off the 3 push tabs in the roof lining.3. as I wanted the inspect the connector, I also unscrewed the righthand outer torx screw to allow the liner to come down a little more.4. having gained enough access to the liner, I disconnected the White and Brown Ariel connecters.5. these were clean and dry so I discounted them as the problem. Though I did remove the Yellow Connector (that feeds the Heated Rear windscreen), and let it hang down away from the Ariel wires. ( as a interference precaution, though probably not relevant)6. next I used a 22mm socket to remove the locknut below the Ariel.7. It is a bit of a wiggle to pull the Ariel out of the hole on top.8. next remove the 3 very small Philips screw in the base.9. now inside the Ariel housing , I found some condensation, and the printed circuit was showing signs of corrosion.10. I know for experience that electrical circuits don't fail intermittently (unless there is a heat problem), so was happy to just spay electrical cleaner on the pcb.11. now to the real problem:- The connection between the pcb and the outer Ariel base is done with a piece of sprung tinned copper strip.12. this had corrosive residue on it, so I again sprayed it and lightly rubbed it with a fine emery paper (240grain , 400 would be better to not completely remove the tin).13. I also bent it up a little more to give a better connection (especially when going over potholes etc.)14. rebuild in reverse order. ( the only hard bit is getting the locknut back on as it has a recess for the cable). I have done a trip of 40 miles today and hey presto - no signal loss.I have attached photos. [attachment=1537]