I am not sure about the convertible top or mechanisms that operate it, but the e30 is a very reliable daily driver. I had an 84 318i and an 84 325e. Both had nearly 300k on the clock when I let them go and they were the most reliable cars I have ever owned. My dad still owns an 85 325e he purchased back in 1990. My 325e was hands down more reliable than my current 94 325i. Repairs and maintenance are much more DIY friendly in the e30 as well as most modern cars.

Downside is that the A/C in the e30 will not blow as cold as modern cars, so you may have a few hot summer days and there is probably only one (driver) airbag, if any in that car.