560SL Convertable Top won't go DOWN !!! Bad Microprocessor?

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1986 560SL... convertable top won't go down automatically -- I hold the red button on the console -- get this, the trunk doesn't even open! I've had the car into the dealer 7 times and they've replaced all 11 microprocessors and changed the hydraulic fluid... it's really burning me up.

Then all of the sudden, after ten minutes, it will work! Sometimes, if it's really cool, it won't work, sometimes when it's really hot it won't work... I can't stand sitting in the parking lot at work in the morning when it has started to rain and I can't get the top to go up !!!

Ok, I'm just joshing -- I've been reading all the posts here and on other boards about the Vario roof on the SLK. I find it a tad scary... the thought of driving around in a car whose prime feature can give up the ghost so... er... easily.

I have a good friend who has an SLK 320 and I've been able to cream him in informal stoplight drag races -- but he wins hands down in the TOP UP or TOP DOWN races. So far, he hasn't had any VARIO problems...
My 560SL is seventeen years old. I have the occasional problem removing the hard top with the center post snagging and I'll have to eventually replace the soft top -- but I've never been unable to put the soft top up or down: what a concept.

My question:

What is a retractable hard top going to be like to live with on a seventeen year old car... or for that matter what will a 129's automatic soft top be like to live with when it's twenty-five years old? Don't get me wrong... I love the SLK's and the SL500's etc... I just really, really wonder what the cars will be like to live with as they age?