The driver's seat back may wear off on some cars with leather seats because seat frame is too sharp at the side support area. A modified seatback came with the 2001 model year and the fix for older Miatas is to replace the driver's side seatback (TSB 016/99, Nov. 1999).
On 1999 Miatas with VINs (vehicle identification number) lower than JM1 NB353*XO 119960 the softtop may tear or gradually come apart, or the top cover fasteners may fly off from wind pressure during driving. Mazda issues a replacement softtop with a modified part stitched at the seams and shortened for a tighter fit (007/99R, May 1999).
An engine rattling noise in neutral can be caused by premature wear of the thrust bearing (002/99, April 1999).
Hard starting or excessive cranking time may be caused by foreign substances accumulating at the fuel pressure regulator valve causing it to stick open. It may be necessary to replace the pressure regulator with a modified part (003/99, May 1999).
When in cruise control vehicle speed may fluctuate because of a transistor malfunction inside the cruise control unit. A modified part with a heavy duty transistor was made available (001/99, March 1999).
A rattling noise may be heard from the main silencer between 1,000-1,300 r.p.m. due to a vibration caused by gas pressure fluctuation inside the main silencer (011/98, Sept. 1998).
A rattling noise from underneath at 3,000 r.p.m. may be a result of the engine harness clips vibrating against the power plant frame. Harness bands (tie-wraps) were made available to prevent the clips from vibrating against the frame (011/98, August 1998).
Paint damage may occur on the body at the rear corners of the trunk opening, caused by the trunk lid rubber cushions contacting the rear corners of the body and peeling the paint - possibly resulting in rust (007/98, May 1998).
(Service bulletin information courtesy of Alldata Corp)