Bee Sting Aerial
The first thing to note is that it is not a quick job and it's a good idea to allow most of a day to do it. It probably can be done quicker than I did but at the risk of ripping the roof lining. I don't know how much a new roof lining is but looking at the roof lining, it looks quite a job to replace.
Anyway, it's a good idea to do the job on a warm day and have a hairdryer handy. The reason for this is that you need to soften the glue holding the lining up around the boot. Firstly remove the rubber seal around the boot. You don't have to take it off, just remove it around the top of the boot.
Now the fun part, pulling the lining down. You will to see where the roof lining overlaps the C pillar lining, use this to find the start on the lip of the boot. You need to carefully peel away at this. Using the hairdryer will help to warm the glue and a small screwdriver lift the lining where you can't get your fingers in. I worked from both sides of the car and moved into the middle of the boot. Don't try to do the job to quickly and watch out for small rips that were present from when it was fitted as these can easily run producing large rips that will be seen from inside the car.
Once the lining is removed from the lip around the boot it can be pulled down towards the front of the car. You will find that you come across some thin foam that is glued to the roof of the car. Carefully separate the foam from the lining. After you have cleared the foam the roof lining will come down easily but the is one more obstacle before you can get to the aerial. There is bar that goes across the roof to give the cushion effect. Three clips hold this up. You will be able to see three semicircles in the lining that allows you to reach the clips. You need to pull the bar out of the clips. I found that one came out by hand but the other two required a small screwdriver prise them out.
Now you will be able to see the aerial. The aerial has two connections, a signal cable and a power cable, as the aerial is an amplifying type. Disconnect the aerial by unscrewing the signal cable and pulling the power cable connector apart. The aerial can now be unbolted. It is helpful to have someone hold the aerial from the outside, as the aerial will start to twist.
When you take the aerial out you will discover that the hole in the roof is square. If you have another Volkswagen aerial then you will be ok but there is a chance that other aerials won't fit the hole. I wouldn't recommend enlarging the hole, as this may affect your paintwork at some point in the future. I had a Hella aerial with a 13mm diameter thread, which fortunately fitted ok. I cut the power connector from the old aerial and soldered this to the power cable on the new aerial. Doing this meant that I didn't have to disconnect the car battery to solder the two wires together. You may have to do this once the aerial is screwed in, as the nut may not fit over the connector.
If there is any paint missing from the roof hole then it's probably a good idea to paint it just in case it some day rusts (at least you can use any colour as it won't be seen). As I said earlier the aerial connection is a screw type and the Hella came with a push in type. I went to the local car accessory shop for a connector and found an adaptor cable that would mate the two connectors. The only problem was that it was a foot long so I had to wrap foam around the excess cable to stop it from rattling.
For the next part I couldn't really make a decision. The rubber at the bottom of the aerial makes the seal but I decided to put a small amount black mastic into the space between the two rubber lips of the seal. The reason that I was worried is that some mastics are corrosive. We have had problems at work with electronic circuits corroding near clear mastic.
The best way to get the aerial straight is to keep the boot open use the VW badge on the boot as a guide to the centre of the car. Stand about eight foot from the front of the car in the centre and line the aerial up with the centre of the badge. Once the aerial is screwed in, it's a good idea to test it so plug it in and give it a try. You may already know this but the aerial works better with the boot closed, my aerial had never worked correctly so this was new to me.
I also did a water test. Put a plastic bag under the aerial to protect the roof lining just in case. Also you will have to fit the rubber seal around the boot otherwise this will leak. I didn't and the water went into the boot but fortunately no harm was done. Now you can pour water over the aerial now and hope.
You can now start to put things back. Make sure all the connectors and most of the cables are covered with foam so that you don't get any rattles. You can also tape up the cables and foam but use masking tape, as it will hold better than adhesive tape. I'm not sure if this will still hold on hot days when the sun has been on it all day.
Next click the bar back up with the three clips and you're onto the final part. You now need to pull the lining tight up to the boot and fasten it around the lip. I worked from one side to the other and found it necessary to apply glue. As I fastened the lining down I reapplied the rubber seal over the part I had just done to hold it down. There are two problems here, the side where I started is not perfectly tight so may be I should have started from the centre but then I would not be able to hold the section down with the seal. The second problem is that I probably didn't use the best glue for the job. I used two-part quick set glue, which we use at work. This glue goes hard so if I need to remove it again I'm going to have problems.
Anyway that's about it, remove tools from boot and go for a drive.