It usually works even on older cars. Using a blow dryer or heat gun is sometimes dangerous to the paint if you're not careful... Here's a copy/paste of two different writeups from various sites:
1)
Nissan Maxima How-To's by housecor :: How to remove dealer stickers/pinstripes
How to remove dealer stickers and pinstripes
Dealers just love to slap their tacky little advertisements on the back of your car. There are also some pretty hideous looking aftermarket pinstripe jobs floating around out there too. And it never ceases to amaze me how few people actually remove the eyesores. Hey,why should you do advertising for your dealership for free? Thankfully, the solution is quick and simple:
Use hair dryer on medium to low heat to soften adhesive. Too high of heat can actually bubble the paint.
Carefully peel back sticker
Remove left over adhesive with WD-40 and a terry cloth towel
2)
Removing a Pinstripe from a Vehicle and Scuff Marks from Plastic Bumpers : DIY Network
Removing a Pinstripe from a Vehicle
If pinstripes are painted on, a body or collision shop would need to remove it.
For a decal pinstripe, you need to use something to break down the glue. A lacquer thinner is a harsh product to use and could damage the paint. If you want to try and use it, put a little on a rag and use it on a small spot first to see what it will do.
There are bug and tar removers and citrus based products that will help break down the adhesion.
Body shops have heavy-duty dryers high heat powered guns they use. You could use your home blow dryer. Put it on high setting and get it close to the decal (figure A) and it will begin to soften the adhesive. Use your fingernail to slowly start peeling the decal.
Tip: Lauren says that you can buy plastic razor blades from a craft store and you could use it instead of possibly damaging your fingernails.