In the past I have owned lots of early 80s diesel mercedes. The discussion group like this has a list of common issues, ie. the standard GM air conditioner is crap, the cruise control will be burnt out etc.
Is there a list for the 2nd gen TLs?

 

yes
we call it the Problems and Fixes section,,look at top of page after you sign in
There are 4-5 specialty areas there
thats oddball stuff and some common things, also scroll down the main list where you posted this, for many more things we encounter..
moisture in headlight= replacement of ballast etc for HID low beams common,
brake light switch...

Ck the very bottem of the main page too, subsections like wash and wax, `the black market` contains sponsored sales threads and private sales from members
for trick parts and stock stuff,,dealers who cut us a deal ,,,

and your new best friend, the DIY list https://acurazine.com/forums/2g-tl-1999-2003-98/new-official-2nd-gen-tl-diy-thread-706083/

off the top of my head for 99: ignition switch fails repeatedly, needs egr port and passage cleaning of the intake manifold every 75kmiles or less (all gen2TL),
everything else is the same as other years

99 4 speed trans more reliable than later years 5 speed

Welcome to the forum

 

register with acura care 1 800 382 2238 x5 and www.owners.acura.com (for usa)
need cars VIN for both
ck for any OPEN recalls