You are unfortunately wrong.
You are correct for the most part: most (probably 99.9%) of regular CD-ROM, CD-R(W) DVD-ROM and DVD+/-R(W) drives, which are ASPI complaint on the software interface level, DO NOT require any drivers in Windows 95 and later (except for ASPI drivers in some cases).
However, most DVD-RAM drives REQUIRE a special driver from their manufacturer in order for their DVD-RAM reading and writing funcions to be utilized. Without that driver, they can be used only as a regular DVD-ROM drive.
The manual for Panasonic LF-D201 DVD-RAM drive clearly states this at page 32. It is located here: http://service.us.panasonic.com/OPERMANPDF/LFD201.PDF
The driver for Windows 2000 should work in Windows XP without problems, because those two operating systems are almost identical. Most differences are of cosmetical nature.
I hope that this helps.