My 380 has been really reliable since I replaced the water pump (about 3 weeks after I bought it). I have had it about 13 months and have only done routine maintenance on it. Great car.
A few things about it:
1. Those damned w126 rear windsheilds.
2. Those damned w126 Climate Control Units.
3. It needs an idle control valve to run completely tip top. $300 for a part the size of a roll of quarters.
4. Rear seat controls dont work. Probably due to non-use.
5. Wood around shifter. Cracked like no tomorrow.
6. Leather needs refinishing.
7. Cigar lighter doesnt like to hold any American 12v appliance cord.
8. Expensive mufflers (but I deserve it for going down a dirt road loaded down heavy.
)
9. Low friggin ground clearance for the under-parts.
Most of these are non-issues, but still annoying. However, they dont outweigh the great benifits of this 20-yr old car.