It is hard to shift into second until the car is warmed up, but switching to a synthetic gear oil cures that. I used Redline synthetic.
The point-type 308 ignition is a weak spot. It has two dual point distributors and the point sets are like $75 each and you have to remove the distributors to change them. I swapped them out with a crane cams Fireball XR-3000 electronic ignition, PS-60 high-power coils, new magnacor plug wires and NGK plugs and did the whole job myself for under $500.
You'll find the power windows are deathly slow, don't let that dissuade you, they're all like that. You can take the doors apart, clean and lube the cables and put it back together in a weekend.
I had the carbs synchronized around 3 years ago. Haven't had to touch them since.
The entire electrical system is fairly weak. Usually just changing out the fuse box cures most of the woes. You can make one yourself or buy a plug-and-play one from Birdman for $100. http://www.birdmanferrari.com/
Speedometer failure is common also. The impulse generator is in a poor spot as it picks up a lot of the water and dirt from the road. A new one of those is like $130.
That's about all I can think of off the top of my head. If you like to turn wrenches you'll find the 308 relatively easy to work on. It's a pretty simple machine. In the 4 1/2 years I've had my car I've spent about $1,500 in maintenance. Heck, I've spent more than that maintaining my truck. The belts were done when I bought the car. I'm planning on doing the belts, idler pulleys and waterpump this winter, haven't looked up all the prices but it will probably run me about a grand to do it right.