Thanks for the link to the list. Of course, it ends at 1997 and the last April Issue Road Test was in the 2012 issue. So, for fans, here's the complete list made up from the autosport.com list and my collection. The ones that are railfan-related in some way are starred (*).

1959?: HMS Trials Replica
1962: San Francisco Cable Car *
1963: London Bus
1964: Morris Major-Mini-Minor
1965: None
1966: Gresley A3 Pacific Locomotive *
1967: Sopwith Camel F.1
1968: Electrophant
1969: Greyhound Bus
1970: Mercedes Benz GT (Garbage Truck)
1971: (January) Jaguar XK-EE Inline-12
1972: Goodyear Blimp
1973: Hop Rod (Diesel) Pogo Stick
1974: Maserati MT-3 Bicycle
1975: Cal Poly Rose Parade Float
1976: None
1977: Arrow JP 770 DW Roller Coaster Car
1978: Quantu-Motion Motorboard (motorized skateboard)
1979: Soarmaster C5A Commuter Special (motorized hang glider)
1980: Willis Flyer (laydown go-cart)
1981: Budweiser Clydesdale 8-Horse Hitch
1982: Route 66 "road" test
1983: Sedan Chair
1984: Kenworth W900 Aerodyne
1985: KSC 554,756 Hardtop (Space shuttle hauler)
1986: Pontiac 0-77 Excitement Hot Air Balloon
1987: Six Italian Urban Electrics (Bumper cars)
1988: Queen Elizabeth 2 versus Concorde
1989: None
1990: North American Mustang P-51D
1991: Hover Dynamics RX2000 (Hovercar)
1992: Runyan Racing 20DT (Dog sled)
1993: JPL Rocky IV Microrover (Martian surface rover)
1994: Three Great Subterrainean Transport Systems (London, Paris, and Tokyo Subways) *
1995: America 3 (America's Cup Yacht)
1996: Indiana Jones Adventure Troop Transport Ride
1997: 1958 Porsche Junior (Tractor)

Continuing based on my collection:

1998: Kassbohrer Pisten Bully 300
1999: 1983 Maxim Hook and Ladder Truck
2000: Ferrarina 0.3 P.T.
2001: HPI Nitro RS4 RACER2 (RC car)
2002: The Monterey Histrionics (Cyclekarts)
2003: 1924 Baldwin Decapod Locomotive *
2004: Wind Wagon
2005: Zamboni 500
2006: Four Angry Cylinders (the Shiftright Special)
2007: Three Superlative Delivery Vehicles (from DHL, FedEx, and UPS)
2008: Racer Motors Mach 5 (Speed Racer's car)
2009: Zeppelin NT N704LZ Eureka
2010: Main Street Pedicab
2011: NASA Endeavour OV-105
2012: Food Fight! (Gourmet Food Truck) & Roach Coach No More (food review)

The magazine was reorganized in 2012, after the Hearst buyout, and moved to MI. There have been no more April Issue "spoof" road tests since 2012. It may be safe to assume that the tradition has ended.

-M