What do you mean by an adjustment? Mine is hard to latch, but that is because it is so tight sine the top is not up and down all the time.
You have to follow the sequence in the manual and don't forget to pull the velcro at the post near the driver and pass side windows at the rear. I really have to push down on the front above the latches to get it right.
The top on a vert should be drum tight, otherwise you will get vibrations.
I know what you mean, sometimes it is necessary to press forward with the heel of your hand at the latchpoints to get the pins in place, and even so they do not easily "pop" in. There have been a number of times that I latch the pass side and then have to unlatch it again because I can't get the driver's side done.
Although the top design was changed in '89 to make it more user friendly, there continued to be criticism when the cars were reviewed, that the raising top was not a simple job.
I almost always leave my top down since (as the nasty ones out there say) this is an example of a garage queen. "Lady" has had 2 previous owners and now only has under 35K. She was stored for the two years prior to my ownership last year. Up til now she only comes out on nice sunny days and according to the prvious owner who got her from a chevy dealer who was the first owner, she has never been in the rain. The top looks like it just drove out of the showroom.
I'm not sure if I can keep this tradition though. I'm sure to get caught in the rain sometime. The tires are still the originals and they will get replaced soon--I'm concerned about the safety of riding around on soon-to-be 14 year old rubber and wouldn't want to be on a wet street with them.
Since it has been stored when I started to drive it I had to replace the alternator, mufflers and the engine intake seal. I had all of the fluids changed except the 6 speed ZF, that is due in the next couple of weeks.
Keep in touch, I don't have contact with many other '89 roadster owners. Check out my website for pics and equipment.