Since 1997 General Motors has sold the Savanna/Express with few changes other than the powertrain and deleting the half ton version a couple years ago. These vans are basic, sturdy, and more than a bit antiquated in the presence of the European versions that have made their way Stateside. However, they ARE durable and with reasonable care will last north of 200,000 miles. I've driven these vans for nearly 20 years and they've been reliable and roadworthy. Their ride quality is great, even on Michigan's decrepit roads, and they do the job of hauling parts and tools with a minimum of fuss.
I've already discussed the tire pressure monitoring system, the cheap door and breakaway window handles. Today, I'm going discuss a cheap fix for the rust-away antenna mounts that result in the antenna falling into the fender. As with most car companies, they are copyrighting and making parts from the aftermarket harder and harder to adapt. There is a connector under the right side of the dash that unplugs and theoretically you could unbolt the old antenna and install the new one easily. You can get these from the dealer or on Ebay for $30 to $50. This would be the 'best' way to fix it, but considering the original design is a bit fragile I try and adapt aftermarket parts when I can.
You will need some wire cutters and strippers, an aftermarket antenna, some electrical tape, silicone caulk, a soldering iron and some solder, a sharp knife and a pair of pliers or adjustable wrench. You want to remove the old antenna and unplug the connector under the dash. You'll want to pop out the grommet from the firewall the old antenna cable goes through. Take the antenna you bought and cut off the connector, then cut the connector off the old one and leave about six inches of cable with that one.
You can install a connector that mates these cables together, but I've found them to be a bit hit or miss as they add another connection that can get loose and interfere with radio reception. Since this is coax cable, you can't just splice this with a wire nut. So try this: Slit the outer cover longitudinally to the cable and peel it off of the shielding and stranded wire. Then cut off the inner insulation exposing the inner wire about 1/4 inch. Do this with both cut wire ends. If you've done this right, there will be unbroken and uncut strands on each wire end. Slip the grommet over the cable. Get your soldering iron hot and solder the two inner ends of the cable together. Tape this joint over, and then solder the shielding together. You can bunch up the strands and then do it. Once this is soldered, wrap it up with tape. Install the antenna and your're done. Maranatha!