I just sold my 1991 MR2. I am an avid bike racer and travel almost every weekend to various races. I constructed a custom rack for my MR2 which I used very successfully for over five years. You can go to http://share.shutterfly.com/osi.jsp?i=EeMNHDhyxbOtA
to see pictures of the bike rack.
I took a standard 4-foot Yakima bike rack crossbar and cut it down to a shorter length. Then I welded some brass, industrial-strength, threaded "shelf levelers" to each end of the bar. The bar is then positioned over the rear engine lid cover and supported with some suction cup hardware. By unscrewing the shelf levelers, pressure is applied to the inside "well" area above the rear engine lid. The Yakima bar is then fitted with standard Yakima hardware to secure the front fork of two bikes and two front wheel holders. The rear wheel of each bike then rests on a towel on the rear spoiler and secured with a standard Yakima strap. Some additional Yakima hardware is used to provide extra support between the bar and the front edge (closed to the rear glass window) of the engine lid cover.
This setup has two big advantages. It doesn't interfere with T-tops (if you have them) and you can drive into your garage without worrying about overhead clearance.
I'll sell the entire setup for $200. The brass industrial levelers alone cost over $80.